block: let elv_register() return void

elv_register() always returns 0, and there isn't anything it does where
it should return an error (the only error condition is so grave that
it's handled with a BUG_ON).

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index a054eef..342448c 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -467,7 +467,9 @@
 
 static int __init deadline_init(void)
 {
-	return elv_register(&iosched_deadline);
+	elv_register(&iosched_deadline);
+
+	return 0;
 }
 
 static void __exit deadline_exit(void)