[ltp] Prevent brightness change for AC events

[Henrique de Moraes Holschuh]

On Fri, 11 Jul 2014, Jochen Spieker wrote:
> What did I miss?

The kernel going berserk over the mess that Win8 ACPI firmware did to ACPI
backlight control.

There are fixes going around the linux-acpi ML for this stuff.  Try removing
the ACPI video module, maybe it helps...

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh