autotest: fix the lineout case

sarien has only lineout node

BUG=b:148645503, b:142701772
TEST=Run audio_AudioVolume.headphone on a sarien DUT
chromeos15-row14a-rack6-host5

Change-Id: Icd39c72b417d4de0da83bb6870c4241b4e2c09fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2032905
Tested-by: En-Shuo Hsu <enshuo@chromium.org>
Auto-Submit: En-Shuo Hsu <enshuo@chromium.org>
Reviewed-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Commit-Queue: En-Shuo Hsu <enshuo@chromium.org>
diff --git a/server/site_tests/audio_AudioVolume/audio_AudioVolume.py b/server/site_tests/audio_AudioVolume/audio_AudioVolume.py
index 1e7427e..a7680a5 100644
--- a/server/site_tests/audio_AudioVolume/audio_AudioVolume.py
+++ b/server/site_tests/audio_AudioVolume/audio_AudioVolume.py
@@ -94,6 +94,8 @@
 
             node_type = audio_test_utils.cros_port_id_to_cras_node_type(
                     source.port_id)
+            if node_type == 'HEADPHONE':
+                node_type = audio_test_utils.get_headphone_node(host)
             audio_facade.set_chrome_active_node_type(node_type, None)
             audio_test_utils.dump_cros_audio_logs(
                     host, audio_facade, self.resultsdir, 'after_select')