move _netinfo and libvirt_nets decleration right before it's used

Change-Id: I8c49201eef9dace3dba8944440989a96c3300442
Signed-off-by: ibarkan <ibarkan@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/35687
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>