MFC r232844: Remove extraneous log message

MFC r232844: Remove extraneous log message

  When ntp switched between PLL and FLL mode it produced a log message
  "kernel time sync status change %04x".  This issue is reported in ntp
  bug 452[1] which claims that this behaviour is normal and the log
  message isn't necessary.  I'm not sure exactly when it was removed, but
  it's gone in the latest ntp release (4.2.6p5).

  [1] http://bugs.ntp.org/show_bug.cgi?id=452

git-svn-id: svn://svn.freebsd.org/base/stable/9@239427 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f