GLOBAL MARKETS- Bank stress test relief lifts European assets

* Investors return to risk after ECB health checks* Euro bank shares power equity resurgence* Brazil markets set for losses after Rousseff election win* Russian stocks rebound, rating downgrade avertedBy John GeddieLONDON, Oct 27 (Reuters) - European stocks, low-rated government bonds and the single currency all rose on Monday as financial markets gave a tentative thumbs-up to euro zone bank healt