MRP-1570 llog: Sync all llog groups on exit

It ensures that all llcd are sent and freed.

Change-Id: I23c37f1c5303d246be6fd33377156bd58107a298
Signed-off-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com>
Reviewed-on: http://morpheus.xyus.xyratex.com:8443/gerrit/1292
Tested-by: Jenkins
Reviewed-by: Alexander Boyko <Alexander_Boyko@xyratex.com>
Reviewed-by: Alexey Lyashkov <Alexey_Lyashkov@xyratex.com>
Tested-by: Alexander Lezhoev <Alexander_Lezhoev@xyratex.com>
Reviewed-by: Vitaly Fertman <Vitaly_Fertman@xyratex.com>