mtd: create_freezable_workqueue() doesn't return an ERR_PTR

The create_freezable_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: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/sm_ftl.c

@@ -1274,10 +1274,10 @@ static struct mtd_blktrans_ops sm_ftl_ops = {
 static __init int sm_module_init(void)
 {
 	int error = 0;
-	cache_flush_workqueue = create_freezable_workqueue("smflush");
 
-	if (IS_ERR(cache_flush_workqueue))
-		return PTR_ERR(cache_flush_workqueue);
+	cache_flush_workqueue = create_freezable_workqueue("smflush");
+	if (!cache_flush_workqueue)
+		return -ENOMEM;
 
 	error = register_mtd_blktrans(&sm_ftl_ops);
 	if (error)