destroy_workqueue() already drains the queue before destroying it, so
there is no need to flush it explicitly.
Remove the redundant flush_workqueue() calls.
This was generated with coccinelle:
@@
expression E;
@@
- 	flush_workqueue(E);
	destroy_workqueue(E);
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
        int bug = 0;
 
        cancel_delayed_work_sync(&dm_bufio_cleanup_old_work);
-       flush_workqueue(dm_bufio_wq);
        destroy_workqueue(dm_bufio_wq);
 
        if (dm_bufio_client_count) {
 
        struct dmz_target *dmz = ti->private;
        int i;
 
-       flush_workqueue(dmz->chunk_wq);
        destroy_workqueue(dmz->chunk_wq);
 
        for (i = 0; i < dmz->nr_ddevs; i++)