HID: elo: kill not flush the work

Flushing a work that reschedules itself is not a sensible operation. It needs
to be killed. Failure to do so leads to a kernel panic in the timer code.

CC: stable@vger.kernel.org
Signed-off-by: Oliver Neukum <ONeukum@suse.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-elo.c

@@ -261,7 +261,7 @@ static void elo_remove(struct hid_device *hdev)
 	struct elo_priv *priv = hid_get_drvdata(hdev);
 
 	hid_hw_stop(hdev);
-	flush_workqueue(wq);
+	cancel_delayed_work_sync(&priv->work);
 	kfree(priv);
 }