zsh: _journalctl: improve support for handling mode args (#3952)
This only completes fields from `journalctl --user` in _journal_fields when `--user`
is used.
It also changes $_sys_service_mgr to include both `--system` and `--user`,
because `journalctl` behaves different from `systemctl` in this regard.
No attempt is made to filter out invalid combinations, e.g. when using both
`--directory` and `--system` (see https://github.com/systemd/systemd/issues/3949).
projects / thirdparty / systemd.git / commit
