x86_64: fix message for cpu exception reason
x86_64: fix message for cpu exception reason

alfred-bratterud/IncludeOS,alfred-bratterud/IncludeOS,AnnikaH/IncludeOS,AnnikaH/IncludeOS,AndreasAakesson/IncludeOS,alfred-bratterud/IncludeOS,AndreasAakesson/IncludeOS,mnordsletten/IncludeOS,AnnikaH/IncludeOS,AndreasAakesson/IncludeOS,mnordsletten/IncludeOS,mnordsletten/IncludeOS,AndreasAakesson/IncludeOS,AnnikaH/IncludeOS,mnordsletten/IncludeOS,hioa-cs/IncludeOS,hioa-cs/IncludeOS,mnordsletten/IncludeOS,hioa-cs/IncludeOS,hioa-cs/IncludeOS,hioa-cs/IncludeOS,AndreasAakesson/IncludeOS,AndreasAakesson/IncludeOS,alfred-bratterud/IncludeOS,alfred-bratterud/IncludeOS,mnordsletten/IncludeOS,AnnikaH/IncludeOS