logging: Use 'Storage' log handler for logging storage reports

This patch enables 23 storage loggers by making them child loggers of the
Storage logger. Before that change all those logs were used the root
handler.

Change-Id: I1dd8cd29377b12dc290f90b7c6bf314d5624a830
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Signed-off-by: Yaniv Bronhaim <ybronhei@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/23924
Reviewed-by: Dan Kenigsberg <danken@redhat.com>