“Smallville” is getting a ninth season, but don’t expect “Supernatural” to go that far. Eric Kripke doesn’t care what the ratings are on The CW … after the fifth season, he’s done. “Despite what the network and studio may or may not want, I don’t have more than five seasons of a story,” Kripke told Entertainment Weekly, according to the New York Post. “I would be willing to make sure there are enough villains and heroes around to continue a new story, but there’s no way I’m doing Season 6.” The show is concluding its fourth season, and The CW has already enthusiastically renewed it for a fifth season. But even if Kripke does leave, it doesn’t necessarily mean the end of “Supernatural.” When Al Gough and Miles Millar left “Smallville,” The CW renewed the show anyway, and …