Log Message:
comms/binkd: tidy.

Clear PKG_DESTDIR_SUPPORT=destdir (not user-destdir). There is no
reason for this that I can find.

Clear MAKE_JOBS_SAFE=no. Other than a cosmetic problem with a
post-build message, the actual issue turns out to be a bmake bug.
(PR 59073) Add a couple small makefile adjustments to cope.

Clear BROKEN_ON_PLATFORM=${LP64PLATFORMS}. This seems to have been set
in 1999 and carried around uncritically ever since, across multiple
updates. It builds cleanly with -Wall on amd64, and while I can't test
(not sure anyone much can test this nowadays) that's usually a good
sign, and in 1999 it was described as "hopeless".

Tidy some pkglint.