Confusion is baked right into the title. Four years after “The Boy” scared up a few bucks at the box office, director William Brent Bell and screenwriter Stacey Menear return with a new vision of what fresh terrors said boy (he’s a doll, okay, why did no one just call this movie “The Doll” and be done with it?) will enact on yet another unsuspecting family. Why “Brahms”? That’s the doll’s name, or the boy’s name (there’s also a boy in the first film, kind of), which might remind moviegoers of the nutso line-blurring in “The Boy.” However, “Brahms” also indicates what Bell and Menear really hope to accomplish: a full retcon of the original that does away with a dizzying amount of given information in service to a cheap sequel and the possibility of continuing a franchise for a film that never expected have one.