inpcb: resort to wildcard hash lookup when checking for TCP port conflict

[glebius]

Summary

On bind(2) TCP sockets do not conflict with existing connected sockets
using the same port. We check only wildcard bound sockets. Instead of
looking through the all connections ports hash and then checking that
foreign address of an inpcb found is a wildcard, just short circuit to wild
hash lookup. Provide a better comment with a reference to the change that
introduced this logic.

Should be no behavior change.

[markj]

sys/netinet/in_pcb.c

956

Code comments should be self-contained, in general we try to avoid references like this.

[glebius]

Duplicate of D57986