olsrd: record why the version check logs "Terminated"

olsrd: record why the version check logs "Terminated"

olsrd leaves through olsr_exit(), which ends the process with
raise(SIGTERM) rather than returning from main, so the shell reports
"Terminated" right after the version banner even for a plain
`olsrd -v`. The pipeline status comes from grep, so the check itself
is unaffected, but the line in the CI log looks like a failure to
anyone reading it.

Note it in the script so the next reader does not go hunting.

Signed-off-by: Josef Schlehofer <redacted>
Co-authored-by: Claude Fable 5 <redacted>