LOS ANGELES (NBC, KYMA) - The Annenberg School for Communication and Journalism at the University of Southern California (USC) had a special guest deliver the keynote speech Friday. Olympic gold medalist Lindsay Vonn attended the school's commencement, addressing the more than 1,200 graduates. Her message was simple as she recounted her crash on the slopes at the Milan-Cortina Olympics. She told the graduates, "The only real failure in life is n…