LU-3881 tests: single-node minimal config in sanity-hsm

LU-3881 tests: single-node minimal config in sanity-hsm

Patch to allow for a minimal configuration to be
automatically setup in sanity-hsm.sh, and for example
to permit the single-node sessions runs like :
./lustre/tests/llmount.sh
./lustre/tests/sanity-hsm.sh

Also changed default mount-point to be monitored by agent
to become $MOUNT2 if $MOUNT_2==y.

Created get_agent_uuid() function to dynamically discover
agent's monitored mount-point.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: I194d4a321ea3bcc169c3811e19b1069749b99e72
Reviewed-on: http://review.whamcloud.com/12982
Tested-by: Maloo <hpdd-maloo@intel.com>
Tested-by: Jenkins
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>