dlm: sanitize work_start() in lowcomms.c

The create_workqueue() returns NULL if failed rather than ERR_PTR().
Fix error checking and remove unnecessary variable 'error'.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lowcomms.c

@@ -1468,22 +1468,19 @@ static void work_stop(void)
 
 static int work_start(void)
 {
-	int error;
 	recv_workqueue = alloc_workqueue("dlm_recv", WQ_MEM_RECLAIM |
 					 WQ_HIGHPRI | WQ_FREEZEABLE, 0);
-	error = IS_ERR(recv_workqueue);
-	if (error) {
-		log_print("can't start dlm_recv %d", error);
-		return error;
+	if (!recv_workqueue) {
+		log_print("can't start dlm_recv");
+		return -ENOMEM;
 	}
 
 	send_workqueue = alloc_workqueue("dlm_send", WQ_MEM_RECLAIM |
 					 WQ_HIGHPRI | WQ_FREEZEABLE, 0);
-	error = IS_ERR(send_workqueue);
-	if (error) {
-		log_print("can't start dlm_send %d", error);
+	if (!send_workqueue) {
+		log_print("can't start dlm_send");
 		destroy_workqueue(recv_workqueue);
-		return error;
+		return -ENOMEM;
 	}
 
 	return 0;