Comedian Michael Che defended former “Saturday Night Live” comic Chris Rock on Saturday’s show. According to Che, everyone has their struggles. “Can we stop pretending everybody knew Jada (Pinkett Smith) had alopecia?” he asked during the show’s “Weekend Update” segment. “As much as we heard about Jada and Will’s personal lives, you can’t expect us to retain everything.” A week ago, her husband Will Smith slapped Rock on stage during the 94th Academy Awards presentation after the Oscars host made a joke about the actress’s hair. She has talked about struggling with alopecia, which causes hair …