Don't hard require /var/lib/rpm

[cgwalters]

This code is suboptimal:

openscap/src/OVAL/probes/unix/linux/rpminfo_probe.c

Line 298 in ecf658f

* Fedora >=36 changed the default dbpath in librpm from /var/lib/rpm to /usr/lib/sysimage/rpm

As bootc images won't have that symlink by default because we want /var to start out empty as much as possible.

    * Therefore, when running openscap on a Fedora >=36 system scanning another systems (such as RHEL, SLES, Fedora<36)
   * openscap's librpm will try to read the rpm db from /usr/lib/sysimage/rpm which doesn't exist and therefore won't work.

In general this kind of "cross OS scanning" is going to get into tricky corner cases. It would seem to be more sustainable to simply fork /usr/bin/rpm in the target environment (as a container).

Alternatively, please at least check if /usr/lib/sysimage/rpm exists and set it as the dbpath first. Or, just try a query with the default config and accept that if it returns content.

[cgwalters]

To be clear we can add that symlink into bootc images, and maybe we'll need to if we keep finding more issues like this...but again on the flip side you are hardcoding to read from a now deprecated path, which would make sense to stop doing.