LOS ANGELES, May 11 (Reuters) - Dennis Farina, a former policeman who built a Hollywood career playing detectives, was arrested on Sunday at Los Angeles International Airport for carrying a loaded gun on his way to board a plane, police said. Farina, 64, told police he brought the .22 caliber, semi-automatic pistol with him on a drive from Arizona to Los Angeles and forgot it was in his briefcase when he tried to pass through airport security, police said in a statement. He was scheduled to take a United Airlines flight to his home in Chicago. "Farina was very apologetic...