ocfs2: no need flush workqueue before destroying it

destroy_workqueue() will do flushing work for us.

Link: http://lkml.kernel.org/r/59E06476.3090502@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/dlmfs/dlmfs.c

@@ -670,7 +670,6 @@ static void __exit exit_dlmfs_fs(void)
 {
 	unregister_filesystem(&dlmfs_fs_type);
 
-	flush_workqueue(user_dlm_worker);
 	destroy_workqueue(user_dlm_worker);
 
 	/*