Tweet on, J.R.! J.R. Smith said he is free to keep using Twitter and he will. Coach Mike Woodson said his threat of shutting down Smith’s account was just that — a threat he is not going to go through with. Smith, despite being fined twice in 20 months for inappropriate tweets, isn’t going to shut himself down. “I’m not going to do that, I just got to be better at policing myself,’’ Smith said Saturday night before the Knicks hosted the Hawks. Smith was fined $25,000 Friday by the NBA for responding to Pistons point guard Brandon Jennings’ tweet that insulted his brother, Chris Smith, who was activated Saturday for the first time because of Metta World Peace’s sore left knee. Smith wrote he would send “his street homies’’ to Detroit. “He just got to clean up,’’ Woodson said. “He’s got to let things roll off his back. Let it go and concentrate on playing.” Asked if he banned Smith from Twitter, Woodson said, “There’s nothing I can do about that. I can’t take that away from him. I don’t have the right to do that.’’ Asked about the meeting, Smith said Woodson gave him “the right message — just about me doing the right thing.’’ Smith said on Friday he didn’t believe what he did merited a fine, especially since he deleted the message quickly. Asked if Jennings broke a code by knocking a player, Smith said, “There’s no loyalty in this game. There’s no player- to-player loyalty, no loyalty to teams, no loyalty to anything in this game. I expect there should be that but there isn’t.’’’ “I don’t know what to be surprised about anymore, honestly,’’ Smith said.