Remove the memmove call on dns_rbtnode_t structure that contains atomics

Calling the plain memmove on the structure that contains atomic members
triggers following TSAN warning (even when we don't really use the
atomic members in the code):

    WARNING: ThreadSanitizer: data race
      Read of size 8 at 0x000000000001 by thread T1 (mutexes: write M1, write M2):
	#0 memmove <null>
	#1 memmove /usr/include/x86_64-linux-gnu/bits/string_fortified.h:40:10
	#2 deletefromlevel lib/dns/rbt.c:2675:3
	#3 dns_rbt_deletenode lib/dns/rbt.c:2143:2
	#4 delete_node lib/dns/rbtdb.c
	#5 decrement_reference lib/dns/rbtdb.c:2202:4
	#6 prune_tree lib/dns/rbtdb.c:2259:3
	#7 dispatch lib/isc/task.c:1152:7
	#8 run lib/isc/task.c:1344:2

      Previous atomic write of size 8 at 0x000000000001 by thread T2 (mutexes: read M3):
	#0 __tsan_atomic64_fetch_sub <null>
	#1 decrement_reference lib/dns/rbtdb.c:2103:7
	#2 detachnode lib/dns/rbtdb.c:5440:6
	#3 dns_db_detachnode lib/dns/db.c:588:2
	#4 qctx_clean lib/ns/query.c:5104:3
	#5 ns_query_done lib/ns/query.c:10868:2
	#6 query_sign_nodata lib/ns/query.c
	#7 query_nodata lib/ns/query.c:8438:11
	#8 query_gotanswer lib/ns/query.c
	#9 query_lookup lib/ns/query.c:5624:10
	#10 ns__query_start lib/ns/query.c:5500:10
	#11 query_setup lib/ns/query.c:5224:11
	#12 ns_query_start lib/ns/query.c:11357:8
	#13 ns__client_request lib/ns/client.c:2166:3
	#14 udp_recv_cb lib/isc/netmgr/udp.c:414:2
	#15 uv__udp_recvmsg /home/ondrej/Projects/tsan/libuv/src/unix/udp.c
	#16 uv__udp_io /home/ondrej/Projects/tsan/libuv/src/unix/udp.c:180:5
	#17 uv__io_poll /home/ondrej/Projects/tsan/libuv/src/unix/linux-core.c:461:11
	#18 uv_run /home/ondrej/Projects/tsan/libuv/src/unix/core.c:385:5
	#19 nm_thread lib/isc/netmgr/netmgr.c:500:11

      Location is heap block of size 132 at 0x000000000030 allocated by thread T3:
	#0 malloc <null>
	#1 default_memalloc lib/isc/mem.c:713:8
	#2 mem_get lib/isc/mem.c:622:8
	#3 mem_allocateunlocked lib/isc/mem.c:1268:8
	#4 isc___mem_allocate lib/isc/mem.c:1288:7
	#5 isc__mem_allocate lib/isc/mem.c:2453:10
	#6 isc___mem_get lib/isc/mem.c:1037:11
	#7 isc__mem_get lib/isc/mem.c:2432:10
	#8 create_node lib/dns/rbt.c:2239:9
	#9 dns_rbt_addnode lib/dns/rbt.c:1435:12
	#10 findnodeintree lib/dns/rbtdb.c:2895:12
	#11 findnode lib/dns/rbtdb.c:2941:10
	#12 dns_db_findnode lib/dns/db.c:439:11
	#13 diff_apply lib/dns/diff.c:306:5
	#14 dns_diff_apply lib/dns/diff.c:459:10
	#15 do_one_tuple lib/ns/update.c:444:11
	#16 update_one_rr lib/ns/update.c:495:10
	#17 update_action lib/ns/update.c:3123:6
	#18 dispatch lib/isc/task.c:1152:7
	#19 run lib/isc/task.c:1344:2

      Mutex M1 is already destroyed.

      Mutex M2 is already destroyed.

      Mutex M3 is already destroyed.

      Thread T1 (running) created by main thread at:
	#0 pthread_create <null>
	#1 isc_thread_create lib/isc/pthreads/thread.c:73:8
	#2 isc_taskmgr_create lib/isc/task.c:1434:3
	#3 create_managers bin/named/main.c:915:11
	#4 setup bin/named/main.c:1223:11
	#5 main bin/named/main.c:1523:2

      Thread T2 (running) created by main thread at:
	#0 pthread_create <null>
	#1 isc_thread_create lib/isc/pthreads/thread.c:73:8
	#2 isc_nm_start lib/isc/netmgr/netmgr.c:223:3
	#3 create_managers bin/named/main.c:909:15
	#4 setup bin/named/main.c:1223:11
	#5 main bin/named/main.c:1523:2

      Thread T3 (running) created by main thread at:
	#0 pthread_create <null>
	#1 isc_thread_create lib/isc/pthreads/thread.c:73:8
	#2 isc_taskmgr_create lib/isc/task.c:1434:3
	#3 create_managers bin/named/main.c:915:11
	#4 setup bin/named/main.c:1223:11
	#5 main bin/named/main.c:1523:2

    SUMMARY: ThreadSanitizer: data race in memmove

(cherry picked from commit 48d54368)
79 jobs for !4154 with 2158-threadsanitizer-data-race-in-memmove-v9_16 in 23 minutes and 45 seconds (queued for 15 seconds)
latest detached
Status Job ID Name Coverage
  Precheck
passed #1170216
amd64 linux
autoreconf

00:00:15

passed #1170218
amd64 linux
clang-format

00:00:17

passed #1170219
amd64 linux
coccinelle

00:03:12

passed #1170220
amd64 linux
danger

00:00:15

passed #1170217
amd64 linux
misc

00:00:17

 
  Build
passed #1170234
amd64 linux
clang:asan

00:03:48

passed #1170238
amd64 linux
clang:buster:amd64

00:01:47

passed #1170241
amd64 libvirt
clang:freebsd11:amd64

00:01:50

passed #1170242
amd64 libvirt
clang:freebsd12:amd64

00:01:40

passed #1170243
amd64 libvirt
clang:openbsd:amd64

00:04:29

passed #1170236
amd64 linux
clang:tsan

00:02:10

passed #1170221
amd64 linux
gcc:alpine3.12:amd64

00:01:40

passed #1170233
amd64 linux
gcc:asan

00:03:24

passed #1170226
amd64 linux
gcc:buster:amd64

00:01:37

passed #1170222
amd64 linux
gcc:centos6:amd64

00:01:22

passed #1170223
amd64 linux
gcc:centos7:amd64

00:01:33

passed #1170224
amd64 linux
gcc:centos8:amd64

00:01:36

passed #1170232
amd64 linux
gcc:focal:amd64

00:01:49

passed #1170237
amd64 linux
gcc:mutexatomics

00:01:39

passed #1170228
amd64 linux
gcc:out-of-tree

00:01:31

passed #1170227
amd64 linux
gcc:sid:amd64

00:02:11

passed #1170229
i386 linux
gcc:sid:i386

00:01:41

passed #1170239
amd64 linux
gcc:softhsm2.4

00:01:36

passed #1170240
amd64 linux
gcc:softhsm2.6

00:01:36

passed #1170225
amd64 linux
gcc:stretch:amd64

00:01:48

passed #1170235
amd64 linux
gcc:tsan

00:02:01

passed #1170230
amd64 linux
gcc:tumbleweed:amd64

00:01:35

passed #1170231
amd64 linux
gcc:xenial:amd64

00:01:45

passed #1170245
amd64 windows
msvc:windows:amd64

00:00:56

passed #1170244
amd64 linux
nolibtool:sid:amd64

00:02:21

 
  Unit
passed #1170258
amd64 linux
unit:clang:asan

00:00:51

passed #1170262
amd64 linux
unit:clang:buster:amd64

00:00:34

passed #1170265
amd64 libvirt
unit:clang:freebsd11:amd64

00:01:02

passed #1170266
amd64 libvirt
unit:clang:freebsd12:amd64

00:01:02

passed #1170260
amd64 linux
unit:clang:tsan

00:01:30

passed #1170246
amd64 linux
unit:gcc:alpine3.12:amd64

00:00:48

passed #1170257
amd64 linux
unit:gcc:asan

00:00:50

passed #1170251
amd64 linux
unit:gcc:buster:amd64

00:00:35

passed #1170247
amd64 linux
unit:gcc:centos6:amd64

00:00:38

passed #1170248
amd64 linux
unit:gcc:centos7:amd64

00:00:42

passed #1170249
amd64 linux
unit:gcc:centos8:amd64

00:00:38

passed #1170256
amd64 linux
unit:gcc:focal:amd64

00:00:36

passed #1170261
amd64 linux
unit:gcc:mutexatomics

00:00:34

passed #1170252
amd64 linux
unit:gcc:sid:amd64

00:00:36

passed #1170253
i386 linux
unit:gcc:sid:i386

00:00:35

passed #1170263
amd64 linux
unit:gcc:softhsm2.4

00:00:34

passed #1170264
amd64 linux
unit:gcc:softhsm2.6

00:00:38

passed #1170250
amd64 linux
unit:gcc:stretch:amd64

00:00:33

passed #1170259
amd64 linux
unit:gcc:tsan

00:01:48

passed #1170254
amd64 linux
unit:gcc:tumbleweed:amd64

00:00:37

passed #1170255
amd64 linux
unit:gcc:xenial:amd64

00:00:38

passed #1170267
amd64 linux
unit:nolibtool:sid:amd64

00:00:49

 
  System
passed #1170280
amd64 linux
system:clang:asan

00:12:21

passed #1170284
amd64 linux
system:clang:buster:amd64

00:10:10

passed #1170287
amd64 libvirt
system:clang:freebsd11:amd64

00:10:14

passed #1170288
amd64 libvirt
system:clang:freebsd12:amd64

00:10:17

failed #1170282
amd64 linux allowed to fail
system:clang:tsan

00:14:21

passed #1170268
amd64 linux
system:gcc:alpine3.12:amd64

00:11:54

passed #1170279
amd64 linux
system:gcc:asan

00:12:48

passed #1170273
amd64 linux
system:gcc:buster:amd64

00:11:25

passed #1170269
amd64 linux
system:gcc:centos6:amd64

00:11:32

passed #1170270
amd64 linux
system:gcc:centos7:amd64

00:11:02

passed #1170271
amd64 linux
system:gcc:centos8:amd64

00:11:51

passed #1170278
amd64 linux
system:gcc:focal:amd64

00:11:24

passed #1170283
amd64 linux
system:gcc:mutexatomics

00:11:11

passed #1170274
amd64 linux
system:gcc:sid:amd64

00:10:48

passed #1170275
i386 linux
system:gcc:sid:i386

00:10:43

passed #1170285
amd64 linux
system:gcc:softhsm2.4

00:10:17

passed #1170286
amd64 linux
system:gcc:softhsm2.6

00:11:00

passed #1170272
amd64 linux
system:gcc:stretch:amd64

00:11:20

failed #1170281
amd64 linux allowed to fail
system:gcc:tsan

00:15:25

passed #1170276
amd64 linux
system:gcc:tumbleweed:amd64

00:11:20

passed #1170277
amd64 linux
system:gcc:xenial:amd64

00:10:14

passed #1170289
amd64 linux
system:nolibtool:sid:amd64

00:11:19

 
  Docs
passed #1170290
amd64 linux
docs

00:01:58

 
  Postcheck
passed #1170294
amd64 linux
cppcheck

00:00:20

passed #1170291
amd64 linux
flake8

00:00:16

passed #1170292
amd64 linux
pylint

00:00:22

passed #1170293
amd64 linux
scan-build

00:09:16

 
Name Stage Failure
failed
system:gcc:tsan System
make: *** [Makefile:491: test] Error 1
Running after_script
Running after script...
$ find bin -name 'tsan.*' -exec python3 util/parse_tsan.py {} \;
Uploading artifacts for failed job
Uploading artifacts...
untracked: found 10046 files

Uploading artifacts as "archive" to coordinator... ok
id=1170281 responseStatus=201 Created token=SX3eTKwE
ERROR: Job failed: exit code 1
failed
system:clang:tsan System
make: *** [Makefile:491: test] Error 1
Running after_script
Running after script...
$ find bin -name 'tsan.*' -exec python3 util/parse_tsan.py {} \;
Uploading artifacts for failed job
Uploading artifacts...
untracked: found 10644 files

Uploading artifacts as "archive" to coordinator... ok
id=1170282 responseStatus=201 Created token=6focuxsj
ERROR: Job failed: exit code 1