fix thinkpad backlight *buntu

## fix thinkpad backlight

http://www.upubuntu.com/2013/04/fix-brightness-keys-not-working-on.html

1. You can check if you have an intel card by running this command:
	ls /sys/class/backlight/

2. If the returned outputs show this:
	(...) intel_backlight

3. Then this solution may work for you. In the same terminal window, enter this command:
	sudo gedit /etc/default/grub

4. Find this line:
	GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

5. Change it to this one:
	GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

6. Save your file and exit, then run this command to update GRUB 2:
	sudo update-grub

7. Finally, reboot your system.