Nicolas Winding Refn isn’t known for his happy endings, but the ending of his latest movie “Drive” seems pretty sunny by comparison. The bad guy gets killed, and the “good” guy drives off into the sunset. But is it? First of all, the driver might be dead after all. And second: Is the driver that good a guy, when you think about it? He’s pretty violent, what with all the head-smashing and face-slapping he does in the movie. Some heroes might be pretty dangerous walking (or driving) the streets.