Just because a movie is a disjointed, clunky oddball of a bizarrely retro misfire doesn’t mean it’s not, well, entertaining. That seems to be the closest thing to a consensus among the first wave of reviews for “Venom,” which represents Sony’s effort to build out its own superhero universe. Now, to be clear, the critics’ scores as tallied are about as dismal as it gets for a big-budget superhero movie.