This report has been updated to attribute a quote to Adam Glazer. Mark A. Flessner, Chicago’s former corporation counsel, has joined Schoenberg Finkel Beederman Bell & Glazer LLC as a partner.It’s a return to his old practice areas after 19 months leading the city’s Law Department.“I was in private practice for 20 years in white-collar criminal defense and internal investigations before I worked for the city,” Flessner said. “I am hoping to rebuild that practice and am confident I …