block: loop: remove redundant code

Code cleanup for removing redundant break in switch case.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 0939f36..b8a0720 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -616,7 +616,6 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
 	default:
 		WARN_ON_ONCE(1);
 		return -EIO;
-		break;
 	}
 }