When a test times out, it needs to be stopped somehow before continuing on

When a test times out, it means that we never made it back to the test shell prompt. So if we try to continue on to the next test, it's not going to work, and we just go into an endless series of test timeouts. I've seen this happen a few times lately. I think if a test times out we need to do something to kill it, and make sure we get back to a shell prompt before continuing on.

One option is to send ^c, but I'm not sure this is sufficient. It may make more sense to just reboot to the test image.