power_supply: ipaq_micro_battery: Fix leaking workqueue

Driver allocates singlethread workqueue in probe but it is not destroyed
during removal.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 00a588f ("power: add driver for battery reading on iPaq h3xxx")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/ipaq_micro_battery.c

@@ -251,6 +251,7 @@ static int micro_batt_remove(struct platform_device *pdev)
 	power_supply_unregister(&micro_ac_power);
 	power_supply_unregister(&micro_batt_power);
 	cancel_delayed_work_sync(&mb->update);
+	destroy_workqueue(mb->wq);
 
 	return 0;
 }