Playing amiable barkeep “Val” to Kate McKinnon’s anxious Hillary Rodham Clinton, the real HRC walked away with the premiere outing of SNL’s 41st season, kidding herself, singing “Lean On Me” and even hanging around long enough to introduce Miley Cyrus, who was doubling as host and musical guest. It was an A+ appearance in a solid B show. (See The Daily Beast video, above.) The cold open featured Donald and Melania Trump (Taran Killam, new to the imitation game following…