Revert "Using old form of zombiereaper"

This reverts commit d1bb20a892d32822e8f04488fb12df0ffea76a04.

This patch didn't resolve the problem, it just fixed the build errors.
Still the import is invalid as zombieReaper located under
/usr/share/vdsm and utils.py runs for site-packages and cannot locate
it. This revert comes aside to backport of
http://gerrit.ovirt.org/#/c/23213/ that arrange the issue.

Change-Id: If6a970cdd17c9dbf5544f68e406e6667344df900
Signed-off-by: Yaniv Bronhaim <ybronhei@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/23228
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Dan Kenigsberg <danken@redhat.com>