build: disable logging framework on rhel6

As rsyslog-mmcount is not yet available in rhel6 variant, this patch
disables logging framework on rhel6 and its dependency

BUG: 1018308
Change-Id: I6b7c04640f8d38055e00c697d1017c7a530463d0
Signed-off-by: Bala.FA <barumuga@redhat.com>
Reviewed-on: http://review.gluster.org/6108
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>