Bug#927379: upgrade-reports: Buster upgrade issue with /var/run

Package: upgrade-reports
Severity: normal

If /var/run is a directory and not a sym-link to /run, systemd-logind.service
will fail to run with the error:

    Failed to connect to system bus: No such file or directory

This caused various issues with the system as users could login but their
session (no /run/user/ directory nor any XDG_* env variables) wasn't setup.

The issue was fixed when I replaced the directory /var/run with a sym-link to
/run.

I believe this was an issue on my system as I've been running my current
installation since the mid 2000s and until Jessie I was using testing. So I
might have hit an edge case where I missed the switch-over to the links in the
wheezy upgrade.

-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.19.0-4-amd64 (SMP w/4 CPU cores)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)