Drop 'size' argument from bio_endio and bi_end_io

As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant.  Remove it.

Now there is no need for bio_endio to subtract the size completed
from bi_size.  So don't do that either.

While we are at it, change bi_end_io to return void.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/md/dm-zero.c b/drivers/md/dm-zero.c
index f314d7d..bdec206 100644
--- a/drivers/md/dm-zero.c
+++ b/drivers/md/dm-zero.c
@@ -43,7 +43,7 @@
 		break;
 	}
 
-	bio_endio(bio, bio->bi_size, 0);
+	bio_endio(bio, 0);
 
 	/* accepted bio, don't make new request */
 	return DM_MAPIO_SUBMITTED;