oeqa/loader: Ensure invalid test names don't trigger a traceback

oe-selftest -r <invalid test name>

currently triggers a traceback. Ensure this doesn't happen and the user gets a
sensible error message.

(From OE-Core rev: f2042bf3638ed4edfb167e7f7d4be6da60997ead)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/core/loader.py

@@ -44,6 +44,8 @@ def _built_modules_dict(modules):
         # Assumption: package and module names do not contain upper case
         # characters, whereas class names do
         m = re.match(r'^(\w+)(?:\.(\w[^.]*)(?:\.([^.]+))?)?$', module, flags=re.ASCII)
+        if not m:
+            continue
 
         module_name, class_name, test_name = m.groups()