No RETURN_GOOD with uninited rr in create_opt_rr

rr-dict.c: In function 'priv_getdns_append_opt_rr':
rr-dict.c:1353:28: warning: 'opt_rr' may be used uninitialized in this function [-Wuninitialized]

src/rr-dict.c

@@ -1295,7 +1295,7 @@ priv_getdns_create_opt_rr(
     result = getdns_dict_create_with_context(context);
     if (!result) {
         getdns_list_destroy(records);
-        return r;
+        return GETDNS_RETURN_MEMORY_ERROR;
     }
     /* cheat */
     r = 0;