MFC r279016:

MFC r279016:

  Make syslogd work in case shutdown() is POSIX-ly correct.

  On POSIX conformant systems, shutdown() should return ENOTCONN when not
  connected. We attempted to fix this once (kern/84761), but this change
  got backed out because it 'breaks code' (r150155).

  I just reapplied the patch and indeed, syslogd fails on startup. Make it
  easier to re-enable this change in the future by paching up syslogd to
  do the right thing.

Sponsored by: Nuxi

git-svn-id: svn://svn.freebsd.org/base/stable/10@280020 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f