LU-9509 tests: fix compilebench timeout

LU-9509 tests: fix compilebench timeout

With ext4 and lustre found compilebench always takes more time in
create dir operation whenever previous same test aborted without
deleting directory. As per test board result, found compilebench
test ran from suite parallel-scale-nfs.sh timedout before running
from suite parallel-scale.sh, so 1st timedout compilebench not
clear data, rerunning compilebench again causes timeout.

Fix is creating different directory on each run of compilebench.

Seagate-bug-id: MRP-3753
Signed-off-by: Jadhav Vikram <jadhav.vikram@seagate.com>
Reviewed-by: Alexander Lezhoev <alexander.lezhoev@seagate.com>
Tested-by: Alexander Lezhoev <alexander.lezhoev@seagate.com>
Reviewed-by: Ashish Purkar <ashish.purkar@seagate.com>
Change-Id: I9b47e28fe5c638f4167c05fb68e46ec5e90de09e
Reviewed-on: https://review.whamcloud.com/27131
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>