Fix handling of TAT sending failures

dns_view_zonecut() may associate the dns_rdataset_t structure passed to
it even if it returns a result different then ISC_R_SUCCESS.  Not
handling this properly may cause a reference leak.  Fix by ensuring
'nameservers' is cleaned up in all relevant failure modes.
16 jobs for 423-fix-handling-of-tat-sending-failures in 8 minutes and 8 seconds (queued for 7 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #25654
amd64 docker linux

00:00:11

 
  Build
passed build:centos:centos6:amd64 #25655
amd64 docker linux

00:02:09

passed build:centos:centos7:amd64 #25656
amd64 docker linux

00:02:18

passed build:clang:debian:sid:amd64 #25657
amd64 docker linux

00:02:52

passed build:clang:debian:sid:i386 #25659
i386 docker linux

00:03:06

passed build:debian:sid:amd64 #25658
amd64 docker linux

00:01:49

passed build:debian:sid:i386 #25660
i386 docker linux

00:01:52

 
  Test
passed systemtest:centos:centos6:amd64 #25666
amd64 docker linux

00:04:48

passed systemtest:centos:centos7:amd64 #25667
linux amd64 docker

00:04:45

passed systemtest:debian:sid:amd64 #25668
amd64 docker linux

00:04:48

passed systemtest:debian:sid:i386 #25669
i386 docker linux

00:04:33

passed unittest:centos:centos6:amd64 #25661
amd64 docker linux

00:00:56

passed unittest:centos:centos7:amd64 #25662
amd64 docker linux

00:01:00

passed unittest:clang:debian:sid:amd64 #25664
amd64 docker linux

00:00:46

passed unittest:debian:sid:amd64 #25663
amd64 docker linux

00:00:50

passed unittest:debian:sid:i386 #25665
i386 docker linux

00:00:51