traffic-control: Ignore failure from a wait command

There’s a race condition between killing a process and waiting for it to
terminate; since this test is run with `set -e`, this can cause the test
to fail if the process dies before `wait` is invoked. Fix that by
ignoring failure from it.

Bug: https://bugs.apertis.org/show_bug.cgi?id=327
Differential Revision: https://phabricator.apertis.org/D426


Signed-off-by: Philip Withnall <philip.withnall@collabora.co.uk>

traffic-control/manual/run-tcmmd-test.sh

@@ -87,7 +87,7 @@ check_decent_speed() {
 
   sleep $WGET_TEST_DURATION
   kill -9 $WGET_PID
-  wait $WGET_PID
+  wait $WGET_PID || true
   sleep 0.2
   whine "Was it a decent speed (1MB/s or more) [yes/no]?"
   read v