runner: Fix message when aborting the test

The message logged in TEST_LOG was hardcoded even though multiple reason
could happen. Let's use the proper reason by using "err" variable which
is correctly used on other places.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

avocado/core/runner.py

@@ -234,8 +234,7 @@ class TestStatus(object):
                 test_state['text_output'] = log_file_obj.read()
         except IOError:
             test_state["text_output"] = "Not available, file not created yet"
-        TEST_LOG.error('ERROR %s -> TestAbortedError: '
-                       'Test process died without reporting the status.',
+        TEST_LOG.error('ERROR %s -> TestAbortedError: %s.', err,
                        test_state['name'])
         if proc.is_alive():
             TEST_LOG.warning("Killing hanged test process %s" % proc.pid)