Update TCPS_HAVERCVDFIN() macro to correctly include all states a connection
can be in after receiving a FIN.

FWIW, NetBSD has this change for quite some time.

This has been tested at Netflix and Limelight in production traffic.

Reported by: Sam Kumar <samkumar99 at gmail.com> on transport@
Reviewed by: rrs
MFC after: 4 weeks
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D7475