After the hundredth time, it’s obvious that “Ice Cream Man” has only one gag. “Ice Cream Man” stars Charlie Zeltzer as Jared, a kid with more bullies than permanent teeth. You could argue the Ice Cream Man is a hypocrite, but Roth’s film never explores that possibility. The backstory for “Ice Cream Man” merely frames the ultraviolence as a dark catharsis, and that’s not convincing. “Ice Cream Man” is a hot fudge sundae without any ice cream, or any hot fudge.