test: remove exit 0 at the end We don't need that at the end, as it will always exit with 0 if everything is okey.

tests: add regression test for `systemctl restart systemd-journald` See https://github.com/systemd/systemd/issues/2236

tests: use sync instead of flush flush doesn't sync a journal -> tests sometimes fail

tests: journal-stdout-stream: add cases for leading and trailing spaces

tests: add basic journal test