LU-4816 tests: Customer Wizard seems to be stuck on test 116

LU-4816 tests: Customer Wizard seems to be stuck on test 116

Due to large OST  size, the execution of test 116 takes huge time to
complete. In such cases it would be good to skip this tests execution.

The test attempts to write 2% above the qos_threshold_rr_level.
In scenarios where OST size is huge, during the first round of write
the count of 2MB file to be created is big, causing testt to take time
to comeplete the same.

This change checks to see if more space is available than expected,
and if so skips the test.

Signed-off-by: Parinay Kondekar <parinay_kondekar@xyratex.com>
Change-Id: Ifa101de2fffcaa3c182582496abd68ab6244d3a0
Xyratex-bug-id: MRP-1747
Reviewed-on: http://review.whamcloud.com/9778
Tested-by: Jenkins
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>