ensure that TRANSFERSTATUS can return FAILURE (issue #5146)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6542 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_transfer.c

@@ -90,10 +90,11 @@ static int transfer_exec(struct ast_channel *chan, void *data)
 
 	res = ast_transfer(chan, dest);
 
-	if (!res) {
+	if (res < 0) {
 		status = "FAILURE";
 		if (option_priority_jumping)
 			ast_goto_if_exists(chan, chan->context, chan->exten, chan->priority + 101);
+		res = 0;
 	} else {
 		status = "SUCCESS";
 		res = 0;