Initialise return value.

src/dnssec.c

@@ -638,6 +638,9 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
   int type_covered, algo, labels, orig_ttl, sig_expiration, sig_inception, key_tag;
   u16 *rr_desc = get_desc(type);
  
+  if (wildcard_out)
+    *wildcard_out = NULL;
+  
   if (!(p = skip_questions(header, plen)))
     return STAT_BOGUS;