block: remove the error_sector argument to blkdev_issue_flush

The argument isn't used by any caller, and drivers don't fill out
bi_sector for flush requests either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/xfs/xfs_super.c

@@ -305,7 +305,7 @@ void
 xfs_blkdev_issue_flush(
 	xfs_buftarg_t		*buftarg)
 {
-	blkdev_issue_flush(buftarg->bt_bdev, GFP_NOFS, NULL);
+	blkdev_issue_flush(buftarg->bt_bdev, GFP_NOFS);
 }
 
 STATIC void