In order to get tracing per test, allow run-tests.py to start
and stop tracing per test case. This is implemented using a
python 'with' context so it starts/stops automatically at the
right spots.
Instead of starting global tracing, also use it from run-all.sh
and put the trace files into the log dir.
Note that this only works right if you use a separate log dir
for all test runs as the trace files aren't timestamped.
Signed-hostap: Johannes Berg <johannes.berg@intel.com>
435e37df7c