NEW YORK — OG Anunoby doesn’t know how it happened — but he knew something was terribly wrong in Charlotte, N.C. It was a Jan. 29 road matchup between the Knicks and Hornets, and after going through pregame warmups, Anunoby determined he was unfit to suit up and play that night. The reason? Inflammation in his right elbow. The same elbow he uses to shoot the 3-ball at a 39% clip since his arrival via the Dec. 31 trade with the Toronto Raptors. These days, Anunoby isn’t doing much shooting at all. He’s been sidelined ever since, and three and a half weeks later, there remains no concrete injury…