[FEATURE] show WARN_ON() results

[plbossart]

Is your feature request related to a problem? Please describe.

So far sof-test only reports the errors. It would be useful to show this type of warnings, which clearly point to something very wrong.

[  562.418115] kernel: WARNING: lock held when returning to user space!
[  562.418117] kernel: 5.15.0-rc1-pr3186-6452-nocodec #6d37c52e Not tainted
[  562.418120] kernel: ------------------------------------------------
[  562.418122] kernel: aplay/8747 is leaving the kernel with locks still held!
[  562.418125] kernel: 1 lock held by aplay/8747:
[  562.418127] kernel:  #0: ffffffffc07673e0 (&card->dpcm_mutex){....}-{3:3}, at: dpcm_be_dai_trigger+0x3da/0x4d0 [snd_soc_core]

Describe the solution you'd like

these lines shown in the output of sof-test scripts and an error status. Maybe in some cases we'll see false positives but we can filter them out

Describe alternatives you've considered
stop on warnings would be too invasive?

[marc-hb]

One problem is neither github nor Jenkins (nor Travis) supports any intermediate "warning" level. It's either PASS or FAIL and nothing available in between. Binary like cable news and social media.

Right now success is based on journalctl -k --priority=err. We can certainly run journalctl -k --priority=warn too but then what do we do with the output? In which place(s) would like this to be displayed and how?

[plbossart]

well that's precisely why I asked, I don't know how to do it.
if we report all the warnings we'll fail all the time. maybe filter and only allow the warnings when we see a pattern of WARNING with a kernel version below and the ---- delimiter.