do not deregister virt classes in yum upgrade
do not deregister virt classes in yum upgrade

  Now yum upgrade will deregister the virt classes, make
libvirt-cim not workable. This patch fixed it from now on.

Signed-off-by: Wenchao Xia <a82bded1b492a49d76e42d0788520e04e9fbf126@linux.vnet.ibm.com>
Reviewed-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

libvirt/libvirt-cim,libvirt/libvirt-cim,libvirt/libvirt-cim