* Importance of Saudi to energy markets is limiting fallout -HSBC. : LONDON, Oct 29 (Reuters) - Saudi Arabia is unlikely to see significant impact on its foreign trade and investment flows following the killing of journalist Jamal Khashoggi, the chief executive of Europe’s biggest bank HSBC said on Monday. “It has been a difficult few weeks for the kingdom, this has not been good for Saudi Arabia,” HSBC CEO John Flint told Reuters in an interview.