Even when U.S. Magistrate Judge Daniel G. Martin was suffering from the pancreatic cancer that ultimately took his life, a longtime friend said, he was still a man “who always had to answer the bell.”Martin approached his work as a judge and a teacher like a boxer, said David A. Erickson, a senior instructor at IIT Chicago-Kent College of Law who serves as director of the trial advocacy program and co-director of the program in criminal litigation.“No matter how bad things are going, you’ve got to …