Who better to play a wrestler than Dwayne Johnson. He will produce and star in “Smashing Machine,” a dramatic movie about the life of two-time UFC champion Mark Kerr. Dwayne, also a former pro wrestler, made the announcement at Madison Square Garden on Friday night during the weigh-in for this weekend’s UFC 244 card. Kerr was a two-time UFC champion who started in the earlier days in the mixed martial arts game.