Small fix for powertop

[Arjan van de Ven]

Pawel Golaszewski wrote:
> Hello,
> 
> This is very small fix for building powertop:
> http://blues.gda.pl/SOURCES/powertop-make.patch
> 
> It allows for real use of DESTDIR feature and allows to override gcc with 
> something else.
> 
> Please, apply.

the patch didn't quite apply (I changed the Makefile since the 1.1 
release) but I've manually put your changes in. Thanks for the feedback!