Removed redundant 'listener != NULL' check.
1191cleanup:
CID 304936 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking listener suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
1192 if (listener != NULL) {
1193 isc_refcount_decrement(&listener->refs);
1194 listener->exiting = true;
1195 free_listener(listener);
1196 }
c4906be2d4