mm: backing-dev: Remove the unneeded result variable

Return the value cgwb_bdi_init() directly instead of storing it in another
redundant variable.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: ye xingchen <[e-mail]>
Reported-by: Zeal Robot <[e-mail]>
Reviewed-by: Andrew Morton <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/backing-dev.c

···
 
 int bdi_init(struct backing_dev_info *bdi)
 {
-	int ret;
-
 	bdi->dev = NULL;
 
 	kref_init(&bdi->refcnt);
···
 	INIT_LIST_HEAD(&bdi->wb_list);
 	init_waitqueue_head(&bdi->wb_waitq);
 
-	ret = cgwb_bdi_init(bdi);
-
-	return ret;
+	return cgwb_bdi_init(bdi);
 }
 
 struct backing_dev_info *bdi_alloc(int node_id)