cifs: cancel_delayed_work() + flush_scheduled_work() -> cancel_delayed_work_sync()

flush_scheduled_work() is going away.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

fs/cifs/cifs_dfs_ref.c

@@ -44,8 +44,7 @@ static void cifs_dfs_expire_automounts(struct work_struct *work)
 void cifs_dfs_release_automount_timer(void)
 {
 	BUG_ON(!list_empty(&cifs_dfs_automount_list));
-	cancel_delayed_work(&cifs_dfs_automount_task);
-	flush_scheduled_work();
+	cancel_delayed_work_sync(&cifs_dfs_automount_task);
 }
 
 /**