The LED luminance level is normally lower when no button is pressed.
Reviewed-by: Eduard Hasenleithner <eduard@hasenleithner.at>
Tested-by: Eduard Hasenleithner <eduard@hasenleithner.at>
Signed-off-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>