ANN ARBOR, Mich. — Kalel Mullings surged 2 yards for a touchdown run on fourth down with 37 seconds left, lifting No. 18 Michigan to a 27-24 win against No. 11 USC on Saturday, welcoming the Trojans to the Big Ten with a heavy dose of smashmouth football.The Wolverines (3-1, 1-0) overcame losing a 14-0…