Glynn Riddle, the CFO of nursing home operator Advocat, on Friday worked his last day on the job — outlasting his successor by almost four months. Riddle had told his board last December that he planned to leave but ended up staying on longer than expected when CFO-in-waiting Sam Daniel left the Brentwood-based company after less than three months on the job. Advocat hasn't yet named a successor to Riddle, which leaves President and CEO Kelly Gill as the company's only named executive officer.