MIDEAST STOCKS-Sinking banks drag down Saudi stocks, rest of region mixed

* Earnings miss at Riyad Bank prompts slide by sector * Oil shipper Bahri sinks on Q4 earnings * Qatar National Bank closes firm despite earnings miss * Egypt's Global Telecom drops on plan to cancel GDRs * But Commercial International Bank climbs on HSBC upgrade By Andrew Torchia DUBAI, Jan 16 (Reuters) - A slide in banking shares after earnings at a major bank missed analysts' estimates dragged down Saudi Arabia's stock market on Monday, while markets in the rest of the region were mixed. ...