ANN ARBOR, Mich. — One step forward, one step back. That’s been the theme of Michigan’s postseason push over the past month and the Wolverines couldn’t buck the trend on Sunday against No. 15 Illinois. This time, a hot-shooting first half by Alfonso Plummer and a big second half by Kofi Cockburn was too much for Michigan to overcome as its late comeback bid fell short in a 93-85 loss at Crisler Center. Grad transfer guard DeVante’ Jones had 25 points and 10 assists, freshman forward Caleb Houstan scored 21 and sophomore center Hunter Dickinson had 13 points and 11 rebounds for Michigan (15-12,…