Kellogg Community College President Dennis Bona is returning to work after an investigation into his interactions with college personnel didn't find evidence of wrongdoing.  Bona last month was placed on non-disciplinary paid administrative leave pending the outcome of the investigation.  Jonathan Byrd, chairman of the school's Board of Trustees, says that the 20-day investigation by outside legal counsel and a private investigative firm found "there was not adequate evidence to substantiate the allegations being investigated." The board voted unanimously Wednesday to take Bona off leave. Bona, who was named president of the school in 2010, says he's pleased with the board's decision.