Attorney General Thomas F. Reilly was unaware until yesterday that a controversial Brockton police lieutenant who retired with a $140,000-a-year pension had been a delegate elected in February to vote for him at the state Democratic convention, his campaign said. At a forum yesterday at Curry College in Milton , Reilly, a Democratic candidate for governor, said the lieutenant, Charles Lincoln, had nothing to do with his campaign. ``We keep getting calls at the station," asked reporter Christine James from WATD-FM in Marshfield. ``Did Charlie Lincoln have anything to do with your election campaign at all?" ``No, no," said Reilly. Later, his campaign aides said Reilly had no idea that Lincoln had been elected a delegate for him from the town of Middleborough.