A United Boeing 767-300, registration N669UA performing flight UA-14 (dep May 31st) from Honolulu,HI to Newark,NJ (USA), was descending towards Newark when the crew reported smoke in the cockpit. The aircraft continued for a safe landing on runway 22L. During the rollout the crew opened the cockpit windows, the aircraft taxied to the apron with emergency services in trail. Emergency services reported the crew reported smoke in the cockpit, a visual inspection after landing did not find any trace of fire, heat or smoke however. The airline reported a mechanical issue.