block: convert blkdev_issue_flush() to use empty barriers

Then we can get rid of ->issue_flush_fn() and all the driver private
implementations of that.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index acf1b81b47cb..0dc563d76b39 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3463,7 +3463,6 @@ static int do_md_stop(mddev_t * mddev, int mode)
                         mddev->pers->stop(mddev);
                         mddev->queue->merge_bvec_fn = NULL;
                         mddev->queue->unplug_fn = NULL;
-                        mddev->queue->issue_flush_fn = NULL;
                         mddev->queue->backing_dev_info.congested_fn = NULL;
                         if (mddev->pers->sync_request)
                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);