Do not count RCTD bit set as an error.

We can not really implement it, but specification tells that it "shall"
work, so it can be safely ignored.

MFC after:	1 week


git-svn-id: svn+ssh://svn.freebsd.org/base/head@275842 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f