domain-conf: cleanup controller insert function
domain-conf: cleanup controller insert function

Signed-off-by: Pavel Hrdina <d4772d05997b8abf035041e3b4f4996380ea7e7a@redhat.com>

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