alsa_conformance_test.py: Fix test under Python 3

Make alsa_conformance_test.py support python3.

BUG=b:145332688
TEST=tast run {DUT_IP} audio.ALSAConformance

Change-Id: I0d5ba2c4cacd09814b30967b9faab4f9ec3e4cca
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/audiotest/+/1940402
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>
Tested-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>
1 file changed