[CFT] Updated devel/valgrind-devel port

[Kyle Evans]

Hello!

Just a little bit ago, I committed an update[0] to the valgrind-devel
port that updates it to Paul Floyd's branch, where he has rebased us
forward to 3.17.0 and largely fixed valgrind operation on both 12.x
and -CURRENT.

He's put in significant effort to get the test suite to pass on
FreeBSD, the status of which is summarized here:
- https://github.com/paulfloyd/freebsd_valgrind/wiki/Regtest-status

Some outstanding issues:
- https://github.com/paulfloyd/freebsd_valgrind/issues

Please go forth and test it!

Thanks,

Kyle Evans

[0] https://svnweb.freebsd.org/changeset/ports/543273