iwlwifi: dvm: handle zero brightness for wifi LED

In order to have the LED being OFF constantly when the
brightness is set to 0, we need to pass IWL_LED_SOLID to
iwl_led_cmd as the off parameter, otherwise the led will
stay on constantly.

This fixes
https://bugzilla.kernel.org/show_bug.cgi?id=110551

Signed-off-by: Hubert Tarasiuk <hubert.tarasiuk@gmail.com>
[reworked the commit message]
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/intel/iwlwifi/dvm/led.c

@@ -152,11 +152,14 @@ static void iwl_led_brightness_set(struct led_classdev *led_cdev,
 {
 	struct iwl_priv *priv = container_of(led_cdev, struct iwl_priv, led);
 	unsigned long on = 0;
+	unsigned long off = 0;
 
 	if (brightness > 0)
 		on = IWL_LED_SOLID;
+	else
+		off = IWL_LED_SOLID;
 
-	iwl_led_cmd(priv, on, 0);
+	iwl_led_cmd(priv, on, off);
 }
 
 static int iwl_led_blink_set(struct led_classdev *led_cdev,