Fix logging typo.
TESTS: Fix WRITESAME tests to handle targets that don't like datalen == 0

Recent SBC specs say (when the WSNZ bit is set to one and the NUMBER OF LOGICAL
BLOCKS field is set to zero) or (if MAXIMUM WRITE SAME LENGTH is greater than 0
and the number of logical blocks specified to be written exceeds the MAXIMUM
WRITE SAME LENGTH) the server should terminate with CHECK CONDITION, set the
sense key to ILLEGAL REQUEST and the additional sense code to INVALID FIELD IN
CDB.

Update the WRITESAME tests to cope with this.
Merge pull request #86 from sitsofe/writesame

Update WRITESAME tests and fix a logging typo