Do the renaming of sb_cc to sb_ccc in a way with less code changes by
using a macro.
This is an alternate approach to
https://svnweb.freebsd.org/changeset/base/275326
which is easier to handle upstream.

Discussed with: rrs, glebius


git-svn-id: svn+ssh://svn.freebsd.org/base/head@275427 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f