staging: greybus: light: Release memory obtained by kasprintf

Free memory region, if gb_lights_channel_config is not successful.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/greybus/light.c

@@ -925,6 +925,8 @@ static void __gb_lights_led_unregister(struct gb_channel *channel)
 		return;
 
 	led_classdev_unregister(cdev);
+	kfree(cdev->name);
+	cdev->name = NULL;
 	channel->led = NULL;
 }