Comment 93 for bug 1510344

Totally the same issue as #92 reported by Roland. Dell E5470. It doesn't matter which value was writed to /sys/devices/platform/dell-laptop/leds/dell::kbd_backlight it always conotains 2. As a result I have keyboard backlight ebabled on every boot, after sleep mode and logout. Solution from #46 and #47 works partially, it helps to avoid enabling backlight on sleep mode and logout but it's still enabled after every reboot.