sysutils/linuxfdisk: Revert "extend port deprecation till end of the year"

This reverts commit 59a3050fa10b54ecda6711921730d6677500392a.

There is no discussion with me nor am I aware of "we", all I see is
that util-linux as a port was stuck, and neither it nor libblkid were
actually ported to FreeBSD - but all the while I was being asked again
and again to move e2fsprogs over to using the util-linux ports, which
seem to have caused regressions for util-linux's fdisk ports.

Now with the libblkid fixes enabling fdisk-linux from util-linux to
at least work on memory disks, let's reset this port to deprecation,
and sharpen the warnings. Using this 22-year old tool without
great care can damage GPT disks and be detrimental to performance or
make devices unable to be used on native 4K block sizes.