If BLockLimits->MaxWriteSameLength is 0 (no limit) or >=256
then verify that both WRITESAME10 and WRITESAME16 can unmap with a
number of blocks == 2 byte field.
If not, then verify that a 256 block unmap results in INVALID FIELD IN CDB
If BLockLimits->MaxWriteSameLength is 0 (no limit) or >=65536
then verify that WRITESAME16 can unmap with a
number of blocks == 3 byte field.
If not, then verify that a 65536 block unmap results in INVALID FIELD IN CDB
From discussions on linux-scsi there are devices that support WRITESAME16
but where the implementation only looks at the low 2 bytes of the 4 bytes for
num-blocks in the CDB.
This added test aims to find and flag such devices.
