autotest: Add a line of logging to ping output parsing

I got an error related to not being able to convert parsed ping output
to floats, and I want to make sure that things like this are easy to
debug for automated runs.

TEST=None
BUG=None

Change-Id: I2797dd4b50578fbed69151501f9070e816dddf88
Reviewed-on: https://gerrit.chromium.org/gerrit/61576
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: Christopher Wiley <wiley@chromium.org>
diff --git a/server/cros/wifi_test_utils.py b/server/cros/wifi_test_utils.py
index dffaa9b..1d79c0c 100644
--- a/server/cros/wifi_test_utils.py
+++ b/server/cros/wifi_test_utils.py
@@ -239,6 +239,7 @@
         stats['avg'] = m.group(3)
         stats['max'] = m.group(4)
         stats['dev'] = m.group(5)
+    logging.debug('Parsed ping stats %r.', stats)
     return stats