tcpsso: support TIME_WAIT state

TCP endpoints in TIME_WAIT are not handled in a special way anymore.
Therefore, they can be handled now by tcpsso.

Reviewed by: rscheff
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D43351

(cherry picked from commit e179d9739b1438ae9acb958f80a983eff7e3dce9)