var-tmpfiles check in bootc container lint doesn't check /etc/tmpfiles.d

[nzwulfin]

Building a workaround for nginx until the RPM update lands downstream with the packaged tmpfiles.d configuration, I created a config in /etc/tmpfiles.d. When I got to the linter output at the end of the build, I noticed that the directories I created in that config weren't checked against the /var filesystem.

[2/2] STEP 12/12: RUN bootc container lint
Lint warning: var-tmpfiles: Found content in /var missing systemd tmpfiles.d entries:
  d /var/lib/dnf 0755 root root - -
  d /var/lib/nginx 0770 nginx root - -
  d /var/lib/nginx/tmp 0770 nginx root - -
  d /var/log/nginx 0711 root root - -

But if I copied the file to /usr/lib, bootc container lint picked up the config

[2/2] STEP 7/13: COPY etc/tmpfiles.d/nginx.conf /usr/lib/tmpfiles.d/
<snip>
[2/2] STEP 13/13: RUN bootc container lint
Lint warning: var-tmpfiles: Found content in /var missing systemd tmpfiles.d entries:
  d /var/lib/dnf 0755 root root - -
  d /var/roothome/.cache 0755 root root - -
  d /var/roothome/.cache/pip 0755 root root - -
  d /var/roothome/.cache/pip/http-v2 0755 root root - -
  d /var/roothome/.cache/pip/http-v2/0 0755 root root - -

We should probably check both /etc and /usr/lib for user added config files since those both valid locations.

[cgwalters]

Yep we should support /etc too, that said it is preferred to have this content in /usr anyways.