Discovery: Create a list of portals for each discovered target.

Some targets return multiple TargetAddress for individual targets.
Create a linked list of addresses for each target instead of
failing the discovery process when this happens.
Corrected the log
Merge pull request #85 from vn516726/master

Corrected the log
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.