“The Last of Robin Hood” is the latest in what has become a series of films taking a revisionist look at Hollywood history. It has a certain amount in common with “My Week With Marilyn,” for instance, since they both attempt to offer insight into the real person behind a cinematic legend. The legend in this case is Errol Flynn (Kevin Kline), who rose to superstardom during the early ’30s, eventually fell from grace thanks to revelations about his lifestyle and drank his way to an ignominious death in 1959.