This patch adds support for ethernet interface type to OpenVZ domains
as stated in this previous message: http://www.redhat.com/archives/libvir-
list/2010-July/msg00658.html
When an openvz domain is defined with virDomainDefineXML,
domain id is set to -1. A call to virDomainGetInfo after
starting the domain would then fail because this invalid
id is passed to openvzGetProcessInfo.