qemu: Fix cgroup handling when setting VCPU BW
qemu: Fix cgroup handling when setting VCPU BW

Commit 632f78c introduced a regression which causes schedinfo being
unable to set some parameters.  When migrating to priv->cgroup there
was missing variable left out and due to passed NULL to underlying
function, the setting failed.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=963592

jfehlig/libvirt,rlaager/libvirt,elmarco/libvirt,zhlcindy/libvirt-1.1.4-maintain,jfehlig/libvirt,olafhering/libvirt,elmarco/libvirt,VenkatDatta/libvirt,eskultety/libvirt,fabianfreyer/libvirt,olafhering/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,taget/libvirt,fabianfreyer/libvirt,eskultety/libvirt,andreabolognani/libvirt,shugaoye/libvirt,cbosdo/libvirt,zhlcindy/libvirt-1.1.4-maintain,shugaoye/libvirt,rlaager/libvirt,agx/libvirt,jardasgit/libvirt,jfehlig/libvirt,cbosdo/libvirt,nertpinx/libvirt,rlaager/libvirt,eskultety/libvirt,VenkatDatta/libvirt,elmarco/libvirt,andreabolognani/libvirt,libvirt/libvirt,olafhering/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,taget/libvirt,zippy2/libvirt,crobinso/libvirt,datto/libvirt,shugaoye/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,zippy2/libvirt,zippy2/libvirt,agx/libvirt,rlaager/libvirt,taget/libvirt,VenkatDatta/libvirt,rlaager/libvirt,eskultety/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,crobinso/libvirt,zhlcindy/libvirt-1.1.4-maintain,agx/libvirt,libvirt/libvirt,VenkatDatta/libvirt,elmarco/libvirt,cbosdo/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,nertpinx/libvirt,cbosdo/libvirt,datto/libvirt,taget/libvirt,nertpinx/libvirt,datto/libvirt,crobinso/libvirt,jardasgit/libvirt,jfehlig/libvirt,eskultety/libvirt,crobinso/libvirt,elmarco/libvirt,datto/libvirt,shugaoye/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,andreabolognani/libvirt,libvirt/libvirt,libvirt/libvirt,agx/libvirt,datto/libvirt,taget/libvirt,zippy2/libvirt,olafhering/libvirt,agx/libvirt