CHICAGO — As Georges Niang’s three-pointer from the right wing fell through the net, Joel Embiid raised both arms into the air. In a duel between two players who will represent the Eastern Conference as starters at All-Star Weekend in two weeks, the 76ers’ superstar could finally celebrate. The Sixers got 40 points from Embiid and survived a 45-point effort from DeMar DeRozan to clinch a 119-108 win Sunday afternoon at the United Center. It was a significant regular-season victory for the Sixers, who snapped a two-game losing skid and moved to 3-0 against a Bulls team that entered Sunday leadi…