SMU quarterback Kevin Jennings threw across the field on 3rd and 10 at Duke and was intercepted with 8:35 to go in the 4th quarter. Even worse, he was helped off the field after being hit low and went to the injury tent. Jennings hasn’t had his usual magic against the Blue Devils. He’s turned the ball over three times on the night while completing 13-of-28 passes for for 258 yards, a touchdown and two interceptions. He’s added 11 carries for 36 yards and a touchdown. SMU quarterback Preston Stone was seen warming up on the sidelines. Stone started the year as the starter, but Kevin Jennings to…