The NBA regular season opened on TNT tonight, and LeBron James and his Cleveland Cavaliers teammates locked arms during the national anthem. No one on the visiting Boston Celtics appeared to take part as a retired Navy man belted out the song. James and some teammates had their heads bowed as the camera showed them near the end of “The Star-Spangled Banner," but there was no kneeling or other obvious protests. During the pregame show, analyst Kenny Smith was asked whether…