Revert "tc-testing: don't access non-existent variable on exception"

This reverts commit 9e3530e42d.

tools/testing/selftests/tc-testing/tdc.py

@@ -129,6 +129,7 @@ class PluginMgr:
             except Exception as ee:
                 print('exception {} in call to pre_case for {} plugin'.
                       format(ee, pgn_inst.__class__))
+                print('test_ordinal is {}'.format(test_ordinal))
                 print('testid is {}'.format(caseinfo['id']))
                 raise