Her hair isn't yet platinum and her makeup is still more girlish than glamorous, but Lana Turner is nonetheless "a walking acetylene torch" in her first top billing, playing a dancer planted in a big Midwest college to win a rigged Hollywood contest. The prize: the starring role in a big movie musical. The complications: plenty, especially when the co-ed falls for a crusading college newshound (Richard Carlson) who suspects the contest