When a connection enters the TCPS_CLOSED state (usually via a tcp_drop()) further BB logging
is not relevant. Connections that hang around in the TCPS_CLOSED state are usually caused
by the application not closing the socket. Holding on to added resources in this case is
unproductive and wasteful. In fact the only thing that could result in doing this is
a connection held open for a SYN attack. And we do not want the resources tied
up nor added logs being generated if that occurred.
Also lets make sure we have proper comments in the tcp_respond() code of when we
would get there with a INP_RLOCK.