Fix --with-kernel for libnfnetlink

[Pablo Neira Ayuso]

On Fri, Apr 21, 2006 at 12:52:10AM +0200, Patrick McHardy wrote:
> KOVACS Krisztian wrote:
> >   Is there any chance of getting the pkg-config related modifications
> > merged as well?
> > 
> >   http://tinyurl.com/mnw9c
> 
> I saw the patch, but didn't apply it because its mostly Harald and
> Pablo who work on that code.
> 
> @Harald, Pablo: any objections against applying this?

No objections from my part, pkg-config is present in most distros AFAIK,
and we needed a way to explicitely set the version dependencies between
libraries.