util: process: fix build on FreeBSD
util: process: fix build on FreeBSD

Commit 825df8c3 refactored virProcess{Set,Get}Affinity routines,
however broke BSD implementation because of the incorrect variable
name. Fix build by using a proper variable name.

Pushing as trivial and build break fix.

jardasgit/libvirt,nertpinx/libvirt,andreabolognani/libvirt,taget/libvirt,agx/libvirt,nertpinx/libvirt,crobinso/libvirt,jardasgit/libvirt,taget/libvirt,rlaager/libvirt,zippy2/libvirt,rlaager/libvirt,datto/libvirt,agx/libvirt,rlaager/libvirt,crobinso/libvirt,eskultety/libvirt,libvirt/libvirt,libvirt/libvirt,taget/libvirt,jardasgit/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,andreabolognani/libvirt,rlaager/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,libvirt/libvirt,olafhering/libvirt,zippy2/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,agx/libvirt,rlaager/libvirt,nertpinx/libvirt,crobinso/libvirt,datto/libvirt,datto/libvirt,andreabolognani/libvirt,agx/libvirt,nertpinx/libvirt,taget/libvirt,olafhering/libvirt,jardasgit/libvirt,zippy2/libvirt,datto/libvirt,libvirt/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,eskultety/libvirt,olafhering/libvirt,VenkatDatta/libvirt,olafhering/libvirt,taget/libvirt,datto/libvirt,jfehlig/libvirt,zippy2/libvirt,crobinso/libvirt,agx/libvirt