TESTS: Start fixing up the tests so we can test-suite them properly

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

test-tool/0410_readtoc_basic.c

@@ -22,8 +22,7 @@
 #include "scsi-lowlevel.h"
 #include "iscsi-test.h"
 
-int T0410_readtoc_basic(const char *initiator, const char *url, int data_loss _U_,
-			int show_info)
+int T0410_readtoc_basic(const char *initiator, const char *url)
 {
 	struct iscsi_context *iscsi;
 	struct scsi_task *task, *task1;