Backlight keys not working on t510 linux

This is due to a kernel error from what I understand.

Here's a quick fix.

apt-get install xbacklight

then add the following bindkeys if you are running fluxbox:
nano .fluxbox/keys

add:
None 232 :Exec xbacklight -dec 5
None 233 :Exec xbacklight -inc 5

Reboot fluxbox