xen_common: Split per-Vif logic from xenParseVif()
xen_common: Split per-Vif logic from xenParseVif()

xenParseVif() does a lot of stuff and, in order to make things cleaner,
let's split it in two new functions:
- xenParseVif(): it's a new function that keeps the old name. It's
responsible for the whole per-Vif logic from the old xenParseVif();
- xenParseVifList(): it's basically the old xenParsePCI(), but now it
just iterates over the list of Vifs, calling xenParsePCI() per each Vif.

This patch is basically preparing the ground for the future when
typesafe virConf acessors will be used.

Signed-off-by: Fabiano Fidêncio <d95e9796398a6087d3fb67947e5776c26b264733@fidencio.org>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

jfehlig/libvirt,eskultety/libvirt,nertpinx/libvirt,crobinso/libvirt,olafhering/libvirt,andreabolognani/libvirt,jardasgit/libvirt,crobinso/libvirt,jardasgit/libvirt,eskultety/libvirt,jardasgit/libvirt,nertpinx/libvirt,libvirt/libvirt,nertpinx/libvirt,libvirt/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,nertpinx/libvirt,jardasgit/libvirt,crobinso/libvirt,zippy2/libvirt,libvirt/libvirt,libvirt/libvirt,eskultety/libvirt,zippy2/libvirt,olafhering/libvirt,andreabolognani/libvirt,zippy2/libvirt,olafhering/libvirt,crobinso/libvirt,fabianfreyer/libvirt,eskultety/libvirt,eskultety/libvirt,zippy2/libvirt,jfehlig/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,jardasgit/libvirt,jfehlig/libvirt,andreabolognani/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,olafhering/libvirt