test-tool: add PrinReadKeys.Truncate test

This test registers PR key and then sends a PR-In read-keys request with
an ALLOCATION LENGTH value that forces response truncation. Ensure that
the ADDITIONAL LENGTH is *not* modified as a result of the truncation.

This test currently passes against TGT but fails against LIO (fix
pending).

Signed-off-by: David Disseldorp <ddiss@suse.de>

test-tool/iscsi-test-cu.c

@@ -158,6 +158,7 @@ static CU_TestInfo tests_preventallow[] = {
 
 static CU_TestInfo tests_prin_read_keys[] = {
         { (char *)"Simple", test_prin_read_keys_simple },
+        { (char *)"Truncate", test_prin_read_keys_truncate },
         CU_TEST_INFO_NULL
 };