Harrison In Hollywood BY PAUL HARRISON NBA Service Staff Correspondent HOLLWOOD--Short takes: A down-and-out horse gambler tugged tugged at the sleeve ol a producer the other day and blurted out a hard- luck story. The producer said: "That sounds pretty good. Put a happy ending on it and come to me at the studio next week." Jimmy Cagney's Christmas cards were a plug for "The Oklahoma Kid"; showed him in western costume costume holding a couple ol guns. John Barrymore's cards were an advertisement for his new picture, "Midnight." Fanny Brice sent out Baby Snooks card with this scrawled scrawled at the bottom: "Daddy says I should wish you a Merry Christmas. Why?" In the monthly Critics Poll, Hollywood Hollywood correspondents who review films chose "The Great Waltz" as the best picture for November and Julien Duvivler as the best director. What the reporters don't seem to know is that Duvivier was dismissed from the assignment and returned to France. Victor Fleming made or remade about three-fourth of "The Great Waltz,"