Fix back port issues: missing checks.

** CID 312923:  Error handling issues  (CHECKED_RETURN)
/lib/dns/zone.c: 11660 in create_query()


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*** CID 312923:  Error handling issues  (CHECKED_RETURN)
/lib/dns/zone.c: 11660 in create_query()
11654     	     dns_message_t **messagep) {
11655     	dns_message_t *message = NULL;
11656     	dns_name_t *qname = NULL;
11657     	dns_rdataset_t *qrdataset = NULL;
11658     	isc_result_t result;
11659     
   CID 312923:  Error handling issues  (CHECKED_RETURN)
   Calling "dns_message_create" without checking return value (as is done elsewhere 17 out of 21 times).
11660     	dns_message_create(zone->mctx, DNS_MESSAGE_INTENTRENDER, &message);
11661     
11662     	message->opcode = dns_opcode_query;
11663     	message->rdclass = zone->rdclass;
11664     
11665     	result = dns_message_gettempname(message, &qname);

** CID 312922:  Error handling issues  (CHECKED_RETURN)
/lib/dns/zone.c: 11994 in stub_request_nameserver_address()


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*** CID 312922:  Error handling issues  (CHECKED_RETURN)
/lib/dns/zone.c: 11994 in stub_request_nameserver_address()
11988     	zone = args->stub->zone;
11989     	request = isc_mem_get(zone->mctx, sizeof(*request));
11990     	request->request = NULL;
11991     	request->args = args;
11992     	request->name = (dns_name_t)DNS_NAME_INITEMPTY;
11993     	request->ipv4 = ipv4;
   CID 312922:  Error handling issues  (CHECKED_RETURN)
   Calling "dns_name_dup" without checking return value (as is done elsewhere 52 out of 60 times).
11994     	dns_name_dup(name, zone->mctx, &request->name);
11995     
11996     	result = create_query(zone, ipv4 ? dns_rdatatype_a : dns_rdatatype_aaaa,
11997     			      &request->name, &message);
11998     	INSIST(result == ISC_R_SUCCESS);
11999