A few months ago, there was “Mirror Mirror,” a fantasy confection that endeavored to turn the “Snow White” fable into a highly stylized circus act with lousy punchlines. While bearable, it wasn’t remarkable. Curiously, movie two in this cinematic fairy tale war, “Snow White and the Huntsman,” takes the opposite storytelling approach, treating the material like it’s dragging a corpse across a fantasyland of doom. The rival “White” is an intentionally joyless creation, investing in a grim atmosphere of murder, sexual perversity, and medieval combat. However, the dwarfs remain, keeping the uneventful effort gasping for gulps of oxygen while it’s being smothered in anger. The producers are obviously trying to butch up an age-old saga of purity and romance, yet by elongating the plot, the filmmakers have inadvertently revealed the source material’s limitations.