Patrick Goldstein takes a look at the buzz for the new straight-to-video feature “Unthinkable,” in which Samuel L. Jackson gets his Jack Bauer on in a ticking-bomb torture scenario and Michael Sheen plays an American Muslim terrorist (Sheen should play more villains; he has real potential as a greasy little malefactor) and is impressed by the film, which ranks 4th on imdb.com’s buzzmeter. Goldstein says the movie has touched off much interesting commentary about torture among message-board users.