The spirit of Count Orlock meets the smiley face in “Yesferatu,” Hills Snyder’s exhibition at Gallery Sonja Roesch. But Smiley, that sunny yellow icon with the vacantly cheery, I’ve-just-had-a-lobotomy grin, is the real star. Snyder extracts the familiar icon from the pop-culture storage shed and turns it into a 21st-century…