Make getRepoStats() a hsm method.

Making repoStats pool independent.

Change-Id: I0273611a23f29b5c6be0354a4c6b2d6526a9b574
Signed-off-by: Eduardo <ewarszaw@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/14673
Reviewed-by: Dan Kenigsberg <danken@redhat.com>