Even after all these years and all these action movies, there is still something credible about Denzel Washington kicking somebody’s ass. While it would be wonderful if Denzel only appeared in films that maximized his charisma, abilities and instincts as an actor, has there ever been a movie star who gets more out of less? Case in point: “The Equalizer,” a possible franchise based on an underrated 1980s TV drama. Denzel plays a nobody, a retiree who works at a cavernous home improvement store in Boston. When a hooker with the heart of gold (Chloë Grace Moretz) gets pummelled by her pimp, he’s out for revenge. But this is some serious revenge — bodies are strewn all over Boston and Denzel barely gets scratched. There are some truly intense scenes with a Russian hitman (Marton Csokas), but “The Equalizer” would be pretty anonymous without another low-key but pitch-perfect Denzel performance.