Prompted by systemd/systemd#16111.
* check if /var is a mountpoint - if not, something went wrong. In case
of systemd/systemd#16111 the /failed file was created, because
systemd-cryptsetup failed, but it ended up being empty, making the result
check incorrectly pass
* forward journal messages to console - if we fail to mount /var,
journald won't flush logs to the persistent storage and we end up
empty handed and with no clue what went wrong
For example, without systemd/systemd#16111 and with this patch:
...
[FAILED] Failed to start systemd-cryptsetup@varcrypt.service.
See 'systemctl status systemd-cryptsetup@varcrypt.service' for details.
[DEPEND] Dependency failed for cryptsetup.target.
...
[ 3.882451] systemd-cryptsetup[581]: Key file /etc/varkey is world-readable. This is not a good idea!
[ 3.883946] systemd-cryptsetup[581]: WARNING: Locking directory /run/cryptsetup is missing!
[ 3.884846] systemd-cryptsetup[581]: Failed to load Bitlocker superblock on device /dev/disk/by-uuid/180ba5ef-873b-4018-9968-47c23431f71a: Invalid argument
...
[ 4.099451] sh[606]: + mountpoint /var
[ 4.100025] sh[603]: + systemctl poweroff --no-block
[ 4.101636] systemd[1]: Finished systemd-user-sessions.service.
[ 4.102598] sh[608]: /var is not a mountpoint
[FAILED] Failed to start testsuite-02.service.