Properly declare AF_IB in the FreeBSD kernel

[• hselasky]

Summary

Instead of using hardcoded value, properly define AF_IB in sys/socket.h

[kib]

Look at cddl/lib/libdtrace/socket.d, I think it needs some update.

Use of AF_MAX in contrib/blacklistd is questionable.

I suggest to ask other people knowledgeable in the socket interface.

[• hselasky]

@kib ping