A kids’ movie for adults who like to pretend they’re still kids, “Chip ‘n Dale: Rescue Rangers” is an exceedingly clever riff on the late ’80s-early ’90s cartoon that is tailor-made for millennials who would come home from school, plop in front of the TV and watch the adventures of the two titular chipmunks, and now have jobs and kids of their own. The Lonely Island’s Akiva Schaffer had to be one of those kids. He directs “Rescue Rangers” with a love and affection for the property like he’s just been handed the keys to the “Batman” franchise. In Schaffer’s hands, along with those of writers Da…