GFS2: alloc_workqueue() doesn't return an ERR_PTR

alloc_workqueue() returns a NULL on error, it doesn't return an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/glock.c

@@ -1838,14 +1838,14 @@ int __init gfs2_glock_init(void)
 
 	glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM |
 					  WQ_HIGHPRI | WQ_FREEZABLE, 0);
-	if (IS_ERR(glock_workqueue))
-		return PTR_ERR(glock_workqueue);
+	if (!glock_workqueue)
+		return -ENOMEM;
 	gfs2_delete_workqueue = alloc_workqueue("delete_workqueue",
 						WQ_MEM_RECLAIM | WQ_FREEZABLE,
 						0);
-	if (IS_ERR(gfs2_delete_workqueue)) {
+	if (!gfs2_delete_workqueue) {
 		destroy_workqueue(glock_workqueue);
-		return PTR_ERR(gfs2_delete_workqueue);
+		return -ENOMEM;
 	}
 
 	register_shrinker(&glock_shrinker);