WASHINGTON - Citing danger to the national economy, the Bush administration approved an emergency bailout of the U.S. auto industry Friday, offering $17.4 billion in rescue loans in exchange for concessions from the deeply troubled carmakers and their workers. The government will have the option of becoming a stockholder in the companies, much as it has with major banks, in effect partially nationalizing the industry. At the same time, Treasury Secretary Henry Paulson said Congress should release the second $350 billion from the financial rescue fund that it approved in October to bail out