CHERRY-PICK: factory_AudioLoop: self._result should be set when test fail.

self._result is undefined when audio_loopback() fails. Assign its default
to False in test setup. And rename it to _test_result to be more clear.

BUG=none
TEST=manual
Use the following test_list:
TEST_LIST = [
    OperatorTest(
        id='InternalMic',
        label_zh=u'内建麦克风',
        autotest_name='factory_AudioLoop',
        dargs={'input_devices': ['hw:0,0'],
               'output_devices': ['hw:0,0'],
               'device_to_mute': 'headphone',
	       'audiofuntest': False}),
]

Reviewed-on: https://gerrit.chromium.org/gerrit/37887
Commit-Ready: Shuo-Peng Liao <deanliao@chromium.org>
Reviewed-by: Shuo-Peng Liao <deanliao@chromium.org>
Tested-by: Shuo-Peng Liao <deanliao@chromium.org>
(cherry picked from commit 97e66df482abfa23a73af3565852d884fcd761c2)

Change-Id: I901964418dc396e869f3f00a7368ec16bb4aa202
Signed-off-by: Dean Liao <deanliao@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/37892
1 file changed