The trick to this “Machete” franchise — And really, did the first film earn enough ($26 million) to warrant a sequel?– is finding funny-violent things for Danny Trejo and his all-star supporting cast (Sofia Vergara, Mel Gibson, Charlie Sheen/Estevez, Lady Gaga? included this time) to do that aren’t given away n the trailer. The films, born as a “Grindhouse” trailer, are funnier as trailers than as full-length features. That said, this trailer made me cackle two or three times. Sept. 13 is when “Machete Kills” opens.