MAN WITH THE IRON FISTS / O.S.T.Offered the opportunity to direct a karate flick and with all the freedom, funding, and flash that an executive producer like Quentin Tarantino would allow Wu Tang leader and kung fu fanatic RZA must have been like a kid in a candy store. Still, the soundtrack to his directorial debut is classic, restrained RZA, as sneaky, restrained, and cool as the Wu when Bobby Digital first landed. After a rap rock opener that's James Bond big with RZA and the