As "make tar" runs tar with a list of files to include in the tarball,

As "make tar" runs tar with a list of files to include in the tarball,
the classic BSD "F" flag, which tells it to *exclude* certain files, is
unnecessary; furthermore, some versions of tar may not support it, and
GNU tar, as appears in FreeBSD and perhaps other BSDs, and in Linux,
interprets the "F" flag as meaning "run, at the end of each archive
volume, the script whose name is given as an argument to the flag", so
it's not even syntactically compatible with the classic "F" flag.

The latter problem causes "make tar" to fail; we remove the "F" flags to
fix the problem.