Address lock order inversions.

WARNING: ThreadSanitizer: lock-order-inversion (potential deadlock) Cycle in lock order graph: M1 (0x000000000000) => M2 (0x000000000000) => M1

Mutex M2 acquired here while holding mutex M1 in thread T1:
#0 pthread_mutex_lock <null>
#1 dns_view_findzonecut lib/dns/view.c:1310:2
#2 fctx_create lib/dns/resolver.c:5070:13
#3 dns_resolver_createfetch lib/dns/resolver.c:10813:12
#4 dns_resolver_prime lib/dns/resolver.c:10442:12
#5 dns_view_find lib/dns/view.c:1176:4
#6 dbfind_name lib/dns/adb.c:3833:11
#7 dns_adb_createfind lib/dns/adb.c:3155:12
#8 findname lib/dns/resolver.c:3497:11
#9 fctx_getaddresses lib/dns/resolver.c:3808:3
#10 fctx_try lib/dns/resolver.c:4197:12
#11 fctx_start lib/dns/resolver.c:4824:4
#12 dispatch lib/isc/task.c:1152:7
#13 run lib/isc/task.c:1344:2

Mutex M1 previously acquired by the same thread here:
#0 pthread_mutex_lock <null>
#1 dns_resolver_createfetch lib/dns/resolver.c:10767:2
#2 dns_resolver_prime lib/dns/resolver.c:10442:12
#3 dns_view_find lib/dns/view.c:1176:4
#4 dbfind_name lib/dns/adb.c:3833:11
#5 dns_adb_createfind lib/dns/adb.c:3155:12
#6 findname lib/dns/resolver.c:3497:11
#7 fctx_getaddresses lib/dns/resolver.c:3808:3
#8 fctx_try lib/dns/resolver.c:4197:12
#9 fctx_start lib/dns/resolver.c:4824:4
#10 dispatch lib/isc/task.c:1152:7
#11 run lib/isc/task.c:1344:2

Mutex M1 acquired here while holding mutex M2 in thread T1:
#0 pthread_mutex_lock <null>
#1 dns_resolver_shutdown lib/dns/resolver.c:10530:4
#2 view_flushanddetach lib/dns/view.c:632:4
#3 dns_view_detach lib/dns/view.c:689:2
#4 qctx_destroy lib/ns/query.c:5152:2
#5 fetch_callback lib/ns/query.c:5749:3
#6 dispatch lib/isc/task.c:1152:7
#7 run lib/isc/task.c:1344:2

Mutex M2 previously acquired by the same thread here:
#0 pthread_mutex_lock <null>
#1 view_flushanddetach lib/dns/view.c:630:3
#2 dns_view_detach lib/dns/view.c:689:2
#3 qctx_destroy lib/ns/query.c:5152:2
#4 fetch_callback lib/ns/query.c:5749:3
#5 dispatch lib/isc/task.c:1152:7
#6 run lib/isc/task.c:1344:2

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

SUMMARY: ThreadSanitizer: lock-order-inversion (potential deadlock) in pthread_mutex_lock

(cherry picked from commit a669c919)

Closes #2156 (closed)