LU-8640 tests: relax time check of sanity-hsm test_16

LU-8640 tests: relax time check of sanity-hsm test_16

If the copytool and test script round clock time in a
different way, a strict time check would causes failure.

Seagate-bug-id: MRP-3436
Signed-off-by: Chennaiah Palla <chennaiah.palla@seagate.com>
Change-Id: Ie30c4366f5f9c4afab64f6825b907bf04d8419ab
Reviewed-on: https://review.whamcloud.com/22725
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>