As of https://cgit.freebsd.org/ports/commit/?id=5b44e3f6b6b24cba2cb0da23b87a6a1c3102cd67, the fprint demo programs are shipped with libfprint. We can retire the fprint_demo port. A patch for that has been submitted here: https://bugs.freebsd.org/bugzilla/attachment.cgi?id=253482 (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=281386).