Dont call READCAPACITY from every single test.
Remove two arguments from the test signatures and turn them into globals.
remove the ret++ silliness. Tests return 0 : all ok, -2, skipped or -1 : test failed
As part of the test also validate the PDU that libiscsi generates and verify that
1, the PDU we send has the F flag set
2, that datasegmentlength for the PDU is one block