Log file cleanup: Only delete temporary file if it was created

[lfittl]

Due to the change in dc4a656 we may
enter cleanup in cases where the TmpFile wasn't actually initialized.

In such cases, we should just do nothing in cleanup.

[msakrejda]

CI failure is the stream_test.go issue we've seen before; restarted the build for now.

[msakrejda]

Restarted for the CI failure a few times now--I think this might be because in handleLogAnalysis we arrange the log lines by backend in a map, and then traverse that (unordered) map to build the result. If I understand this correctly, this is correct but not deterministic. I'm not sure how to solve this, though: attempting to sort in handleLogAnalysis just for determinism seems like overkill, and I don't know if there's a reasonable way to sort this in the test for verifying test behavior. Thoughts?

[lfittl]

@uhoh-itsmaciek I think we need to add an explicit sort in handleLogAnalysis, can't think of a better way to solve this unfortunately. I can look into that.

(merged now since CI did end up being green after a while)