platform/x86: samsung-laptop: Drop duplicate check for led_classdev_unregister()

led_classdev_unregister() already has the very same check, so,
drop a duplicate in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/samsung-laptop.c

@@ -1138,7 +1138,6 @@ static enum led_brightness kbd_led_get(struct led_classdev *led_cdev)
 
 static void samsung_leds_exit(struct samsung_laptop *samsung)
 {
-	if (!IS_ERR_OR_NULL(samsung->kbd_led.dev))
 	led_classdev_unregister(&samsung->kbd_led);
 	if (samsung->led_workqueue)
 		destroy_workqueue(samsung->led_workqueue);