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/8@239467 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f