Major South Korean portal Daum will temporarily close its comments sections on entertainment news, operator Kakao Corp said on Friday, after the death of a K-pop star who had opposed cyber bullying.Sulli, a former member of top South Korean girl group f (x), who had spoken out against cyber bullying, was found dead on October 14 aged 25, with police saying she had been suffering from severe depression.Her apparent suicide prompted an outpouring of grief and calls to rein in the cyber bulling…