LU-9931 tests: : fix REQFAIL calculation

LU-9931 tests: : fix REQFAIL calculation

REQFAIL is the number of times that a sleep is allowed to be
less than $MINSLEEP before the test is considered a fail.
The result of
  "DURATION / SERVER_FAILOVER_PERIOD * REQFAIL_PERCENT / 100"
may not be an integer (165.6) and test fails with :
  "Failed to load with for a minimum
  period of 166 times ( REQFAIL=165 )".
Patch rounds up REQFAIL value for such case.

Test-Parameters: clients=3 testlist=recovery-mds-scale,recovery-random-scale
Seagate-bug-id: MRP-4412
Signed-off-by: Elena Gryaznova <elena.gryaznova@seagate.com>
Reviewed-by: Vladimir Saveliev <vladimir.saveliev@seagate.com>
Reviewed-by: Andriy Skulysh <andriy.skulysh@seagate.com>
Change-Id: I9234de09bc156b1580cab01fcae80a57722fa9d7
Reviewed-on: https://review.whamcloud.com/28797
Tested-by: Jenkins
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Arshad Hussain <arshad.hussain@seagate.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>