LU-8415 tests: customise MPIRUN

LU-8415 tests: customise MPIRUN

Sometimes it is required to use Hydra process
manager instead of mpirun.

Test-Parameters: trivial testlist=performance-sanity

Seagate-bug-id: MRP-3191
Signed-off-by: Elena Gryaznova <elena.gryaznova@seagate.com>
Reviewed-by: Vladimir Saveliev <vladimir.saveliev@seagate.com>
Reviewed-by: Alexander Zarochentsev <alexander.zarochentsev@seagate.com>
Change-Id: I49d6cf3e01214715f577f6364f2cf27ec1d70fd3
Reviewed-on: http://review.whamcloud.com/21431
Reviewed-by: Jian Yu <jian.yu@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>