leds: Fix sparse warning in leds-ams-delta

drivers/leds/leds-ams-delta.c:154:2: warning: returning void-valued expression
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Signed-off-by: NRichard Purdie <rpurdie@linux.intel.com>

drivers/leds/leds-ams-delta.c

@@ -151,7 +151,7 @@ static int __init ams_delta_led_init(void)
 
 static void __exit ams_delta_led_exit(void)
 {
-	return platform_driver_unregister(&ams_delta_led_driver);
+	platform_driver_unregister(&ams_delta_led_driver);
 }
 
 module_init(ams_delta_led_init);