There’s nothing funny about real-life identity theft, but that didn’t stop screenwriter Craig Mazin and director Seth Gordon from attempting to milk laughs from the subject. In “Identity Thief,” the pair tell the story of Sandy Patterson (Jason Bateman), a finance executive who gets swindled by a shameless female grifter named Diana (Melissa McCarthy). Diana starts by stealing Sandy’s unisex name. Then, she runs up masses of credit card debt, ruins his reputation and triggers a warrant for his arrest.