unless it's in the closed or listening state (remote address
== INADDR_ANY).
If a TCP inpcb is in any other state, it's impossible to steal
its local port or use it for port theft. And if there are
both closed/listening and connected TCP inpcbs on the same
localIP:port couple, the call to in_pcblookup_local() will
find the former due to the design of that function.
No objections raised in: -net, -arch
MFC after: 1 month
4658dc8325