Cannot open log file /var/log/ntp.log when starting ntpd service.

Issue

• Getting logs below while starting ntpd service

  # systemctl status ntpd -l
  ● ntpd.service - Network Time Service
   Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled; vendor     preset: disabled)
   Active: active (running) since Tue 2019-06-04 12:59:56 AEST; 3min 16s       ago
   Process: 66559 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS)
   Main PID: 66560 (ntpd)
   CGroup: /system.slice/ntpd.service
         └─66560 /usr/sbin/ntpd -u ntp:ntp -g -u ntp:ntp
  
  Jun 04 12:59:56 node1 ntpd[66560]: Cannot open log file /var/log/ntp.log