fix osmo-gsm-tester.py -t option

Option to select test names had code rot. Use loaded suite definitions
properly.

Change-Id: I24f0a87a017f211f3a30fb98556a392f2a35be7b
diff --git a/src/osmo-gsm-tester.py b/src/osmo-gsm-tester.py
index 17b16b7..34e5fbd 100755
--- a/src/osmo-gsm-tester.py
+++ b/src/osmo-gsm-tester.py
@@ -130,8 +130,8 @@
     test_names = []
     for test_name in (args.test or []):
         found = False
-        for suite_run in suite_runs:
-            for test in suite_run.definition.tests:
+        for suite_scenario_str, suite_def, scenarios in suite_scenarios:
+            for test in suite_def.tests:
                 if test_name in test.name():
                     found = True
                     test_names.append(test.name())