Oscar-winning actor Dustin Hoffman might be ready to say goodbye to Hollywood after his latest film Megalopolis has been panned by critics. RadarOnline.com can reveal Hoffman may retire from acting after the lukewarm reception to the movie he thought would put an exclamation point on his legendary career. A source said: “Dustin knows his legacy is secure with his films like Tootsie, Rain Man and Kramer vs. Kramer. “But he really hoped he had one more legendary film left in him, so he hitched his star to one of the most accomplished film directors of all time, Francis Ford Coppola. “It crushes …