snmp_pf: fix pfInterfacesIfRefsState

pfInterfacesIfRefsState was described as 'Null', which upset bsnmpwalk's attempt
to resolve OIDs to symbolic names:

bsnmpwalk: Error adding leaf pfInterfacesIfRefsState to list

This was done back in d6d3f01e0a339, because we don't return this value any
more. Return it to 'Unsigned32', which fixes things, even if we still don't
actually return this value.

While here update the ORGANIZATION to reflect current ownership.

Reviewed by: philip
MFC after: 2 weeks
Event: Tokyo Hackathon 202503
Differential Revision: https://reviews.freebsd.org/D49413