ci: Fix logs checking in Cirrus-CI jobs.

[dceara]

The check stage only cares about the last instruction's exit code. Run all checks inside a script that fails on the first error.

[dceara]

CC: @igsilya

[igsilya]

OK. The main issue here is the negation. It's treated as a subshell, so errexit is not effective. We need to generate the exit manually it seems.

[dceara]

OK. The main issue here is the negation. It's treated as a subshell, so errexit is not effective. We need to generate the exit manually it seems.

You're right. I added explicit exits now.