The problem with failed `/var` unmount placed on separate partition
have a long story: https://github.com/systemd/systemd/issues/867
According messages after the fix integrated into upstream -- there are
some corner cases which aren't fully fixed by patches adding [relinquish
options](pkg/systemd!26

)

In case of ostree-based images we have a similar issue since `/var` is
bind-mounted in initramfs. Systemd is trying to unmount `/var` on
shutdown, however `ExecStop=` command from `systemd-journal-flush`
service is not executed during shutdown.
By adding `PartOf=var.mount` into service file we force the
`systemd-journal-flush.service` to be called prior the `/var` unmount.
This allow to unlock the bind-mount, since `journald` have a chance to
re-link it's journal into `/run` with `journalctl
--smart-relinquish-var` call.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>

Backported PR 16424 to avoid message
'Failed to parse bus message: Invalid argument'
with an updated kernel using new capabilities.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>

Newer version of systemd-journald support the --relinquish and
--smart-relinquish options that enable cleaner handling of mounts at
shutdown as journald can be told to close any logging under
/var/log/journal so that the /var filesystem can be unmounted should it be
on a separate partition.

Backport this feature as it enables shutdown without failures, a highly
desirable trait in embedded products using systemd.

The significant changes from the upstream patches are:

* Including `util.h` rather than `errno-util.h`, as the functionality
  hasn't been split out into a separate header file in our version.
  https://gitlab.apertis.org/pkg/target/systemd/-/merge_requests/26/diffs#10b30dfe96faf3663f42076bdb4984ccdea14817_0_88
- Adding `ERRNO_IS_ACCEPT_AGAIN` to `varlink.c` (the header file it's
  expected to be in doesn't exist in our version)
  https://gitlab.apertis.org/pkg/target/systemd/-/merge_requests/26/diffs#10b30dfe96faf3663f42076bdb4984ccdea14817_0_93
- Working around the changed parameters for
  `JSON_VARIANT_OBJECT_FOREACH`, adding a call to
  `json_variant_string()`, based on how upstream was modified when the
  macro changed
  https://gitlab.apertis.org/pkg/target/systemd/-/merge_requests/26/diffs#10b30dfe96faf3663f42076bdb4984ccdea14817_0_772
- Expanding the code around `inotify_add_watch()` which got factored out
  to a function in newer versions of systemd
  https://gitlab.apertis.org/pkg/target/systemd/-/merge_requests/26/diffs#f4174ac09c9ebd5278fe22a02b6207223a00f92e_0_74



Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

Signed-off-by: Frédéric Dalleau <frederic.dalleau@collabora.com>

Signed-off-by: Ritesh Raj Sarraf <ritesh.sarraf@collabora.com>

Refresh patches against the latest bashism changes from Buster.
Also, ignore some additional code related to INITRD_OPTIONS

Signed-off-by: Ritesh Raj Sarraf <ritesh.sarraf@collabora.com>