openapi/dbv0.0.37 - correct check of list_for_each() output in _dump_stats_user_list

Bug 13255

NEWS

@@ -63,6 +63,8 @@ documents those changes that are of interest to users and administrators.
  -- Fix batch jobs not resolving the username when nss_slurm is enabled.
  -- slurmrestd - Avoid slurmrestd ignoring invalid HTTP method if the response
     serialized without error.
+ -- openapi/dbv0.0.37 - Correct conditional that caused the diag output to
+    give an internal server error status on success.
 * Changes in Slurm 21.08.5
 ==========================

src/plugins/openapi/dbv0.0.37/parse.c

@@ -2540,7 +2540,7 @@ static int _dump_stats_user_list(const parser_t *const parse, void *obj,
 	xassert(data_get_type(dst) == DATA_TYPE_NULL);
 	args.users = data_set_list(dst);
 
-	if (list_for_each(*user_list, _foreach_stats_user_rpc, &args))
+	if (list_for_each(*user_list, _foreach_stats_user_rpc, &args) < 0)
 		return ESLURM_DATA_CONV_FAILED;
 
 	return SLURM_SUCCESS;