PACKAGE_TARNAME was added on commit 87e7b31 ("Configure Debian package
with AA and SELinux options", 2020-05-13) / PR netblue30#3414.

TOP was added on commit ed4a24c ("porting make deb-apparmor from LTS
build", 2019-01-26).

This (mostly) restores the behavior from before commit 1fb814e
("Makefile.in: stop running distclean on dist", 2022-05-13) / PR netblue30#5142.
./configure still has to be called before calling ./contrib/fj-mkdeb.py
(to generate Makefile from Makefile.in before calling `make distclean`).

Currently, mkdeb.sh (which is used to make a .deb package) runs
./configure with hardcoded options (some of which are automatically
detected based on configure-time variables).  To work around the
hardcoding, contrib/fj-mkdeb.py is used to add additional options by
rewriting the actual call to ./configure on mkdeb.sh.  For example, the
following invocation adds --disable-firetunnel to mkdeb.sh:

    $ ./configure && ./contrib/fj-mkdeb.py --disable-firetunnel

To avoid depending on another script and to avoid re-generating
mkdeb.sh, just let the latter pass the remaining arguments (the first
one is an optional package filename suffix) to ./configure directly.
Example:

    $ make distclean && ./configure && make dist &&
      ./mkdeb.sh "" --disable-firetunnel

Additionally, change contrib/fj-mkdeb.py to do roughly the same as the
above example, by simply forwarding the arguments that it receives to
./mkdeb.sh (which then forwards them to ./configure).  Also, remove the
--only-fix-mkdeb option, since the script does not change mkdeb.sh
anymore.  With these changes, the script's usage (other than when using
--only-fix-mkdeb) should remain the same.

Note: To clean the generated files and then make a .deb package using
the default configuration, the invocation is still the same:

    $ make distclean && ./configure && make deb

Note2: Running ./configure in the above examples is only needed for
generating Makefile/mkdeb.sh from Makefile.in/mkdeb.sh.in after running
distclean, so that running `make` / `./mkdeb.sh` afterwards works.

Should fully fix netblue30#772.

Relates to netblue30#1205 netblue30#3414 netblue30#5148.