The arch wiki has an alternative fix. They just suggest this in your xorg.conf.
Section "Device"
Identifier "Card0"
Driver "intel"
Option "Backlight" "intel_backlight"
EndSection
It fixed it for me.
For more go here and search for xbacklight.
https://wiki.archlinux.org/index.php/Backlight
signature.asc
Description: PGP signature
