I just send xinetd logging to ntp.log (tried to send it to his own log just in case, but couldn't). It's probably not a permanent solution, i guess syslog.conf file will be rewritten on reboot.
Just change this two lines on /etc/syslog.conf and restart the syslogd service
!ntp,ntpd,ntpdate,xinetd
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!-xinetd,ntp,ntpd,ntpdate,charon,ipsec_starter,openvpn,….