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/include/linux/elevator.h b/include/linux/elevator.h
index e8f4213..639624b 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -119,7 +119,7 @@
 /*
  * io scheduler registration
  */
-extern int elv_register(struct elevator_type *);
+extern void elv_register(struct elevator_type *);
 extern void elv_unregister(struct elevator_type *);
 
 /*