ar9170: fix LED power state handling

This patch fixes a minor visual bug in the led code, which
left the LED in the wrong power state when it was toggled
in a _unexpected_ way (e.g: enabling the LED twice).
Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ar9170/ar9170.h

@@ -91,6 +91,7 @@ struct ar9170_led {
 	struct led_classdev l;
 	char name[32];
 	unsigned int toggled;
+	bool last_state;
 	bool registered;
 };
 

drivers/net/wireless/ath/ar9170/led.c

@@ -101,9 +101,12 @@ static void ar9170_led_brightness_set(struct led_classdev *led,
 	struct ar9170_led *arl = container_of(led, struct ar9170_led, l);
 	struct ar9170 *ar = arl->ar;
 
-	arl->toggled++;
+	if (arl->last_state != !!brightness) {
+		arl->toggled++;
+		arl->last_state = !!brightness;
+	}
 
-	if (likely(IS_ACCEPTING_CMD(ar) && brightness))
+	if (likely(IS_ACCEPTING_CMD(ar) && arl->toggled))
 		queue_delayed_work(ar->hw->workqueue, &ar->led_work, HZ/10);
 }