command line, guest console output missing from avocado log

[Peter Maydell]

I just noticed that the guest console output seems to no longer
be in the avocado log file. Can it be reinstated, please?
The console logs are typically the most useful clue to "why did this
test fail" and without it you're just guessing in the dark...
The details of what QEMU command line avocado is running
also seem to have vanished : that also is among the most
useful items of information to have in the log.

thanks
-- PMM