HID: elan: Remove elan_mute_led_get_brigtness()

The led_classdev already contains a cached value of the last set
brightness, the brightness_get callback is only meant for LED drivers
which can read back the actual / current brightness from the hardware.

Since elan_mute_led_get_brigtness() just returns the last set value
it does not add any functionality, so we can just remove it.
Reviewed-by: Marek Behún <kabel@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-elan.c

@@ -410,15 +410,6 @@ static int elan_start_multitouch(struct hid_device *hdev)
 	return 0;
 }
 
-static enum led_brightness elan_mute_led_get_brigtness(struct led_classdev *led_cdev)
-{
-	struct device *dev = led_cdev->dev->parent;
-	struct hid_device *hdev = to_hid_device(dev);
-	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
-
-	return drvdata->mute_led_state;
-}
-
 static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
 				       enum led_brightness value)
 {
@@ -461,7 +452,6 @@ static int elan_init_mute_led(struct hid_device *hdev)
 
 	mute_led->name = "elan:red:mute";
 	mute_led->default_trigger = "audio-mute";
-	mute_led->brightness_get = elan_mute_led_get_brigtness;
 	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
 	mute_led->max_brightness = LED_ON;
 	mute_led->flags = LED_HW_PLUGGABLE;