CID 316785: Error handling issues in dns_transport_list_new() (CHECKED_RETURN)

This came with the initial commit of the file (e488309d):

*** CID 316785:  Error handling issues  (CHECKED_RETURN)
/lib/dns/transport.c: 292 in dns_transport_list_new()
286     dns_transport_list_t *
287     dns_transport_list_new(isc_mem_t *mctx) {
288     	dns_transport_list_t *list = isc_mem_get(mctx, sizeof(*list));
289     
290     	*list = (dns_transport_list_t){ 0 };
291     
>>>     CID 316785:  Error handling issues  (CHECKED_RETURN)
>>>     Calling "isc_rwlock_init" without checking return value (as is done elsewhere 17 out of 21 times).
292     	isc_rwlock_init(&list->lock, 0, 0);
293     
294     	isc_mem_attach(mctx, &list->mctx);
295     	isc_refcount_init(&list->references, 1);
296     
297     	list->magic = TRANSPORT_LIST_MAGIC;