The holiday season seems to creep up earlier and earlier every year. Sure enough, it’s not even Labor Day and there’s already a movie with “Christmas” in its title now playing in theaters and video on demand. But don’t roll your eyes at Chicago writer-director Joe Swanberg. “Happy Christmas” is most certainly not a “Christmas movie.” Yes, it takes place roughly around the holiday season. Yes, it involves family members returning home. But there are no carolers, …