lxc: skip the netdev autogenerated name counter past existing devices
lxc: skip the netdev autogenerated name counter past existing devices

the lxc driver uses virNetDevGenerateName() for its veth device names
since patch 2dd0fb492, so it should be using virNetDevReserveName()
during daemon restart/reconnect to skip over the device names that are
in use.

Signed-off-by: Laine Stump <c23361c43fbf79fed83e8b76173707b083d6caf5@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

libvirt/libvirt,zippy2/libvirt,nertpinx/libvirt,libvirt/libvirt,libvirt/libvirt,jfehlig/libvirt,olafhering/libvirt,jfehlig/libvirt,crobinso/libvirt,nertpinx/libvirt,crobinso/libvirt,jfehlig/libvirt,crobinso/libvirt,nertpinx/libvirt,zippy2/libvirt,nertpinx/libvirt,olafhering/libvirt,olafhering/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,crobinso/libvirt,olafhering/libvirt,zippy2/libvirt,nertpinx/libvirt