LU-5668 test: enable ior data consistency check

Check file content (-W) is consistent during read phase of IOR
and also change task ordering to n+1 ordering for readback (-C).

Test-Parameters: testlist=parallel-scale

Signed-off-by: Johann Lombardi <johann.lombardi@intel.com>
Change-Id: Ic9b1c3cda48ebd08907a6251f62cf2c845d00476
Reviewed-on: http://review.whamcloud.com/12058
Tested-by: Jenkins
Reviewed-by: Li Wei <wei.g.li@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>