J.T. Poston’s 2-under-par 69 in Sunday’s final round was enough to secure a three-shot win at the John Deere Classic in Silvis, Ill. Poston led wire to wire at TPC Deere Run after opening the week with a 9-under 62. He finished at 21-under 263, three better than Christiaan Bezuidenhout of South Africa and Emiliano…