* Italian and Spanish stock markets fall* Traders cite concerns over European elections this week* Rising demand for protection against FTSE MIB falling* FTSEurofirst 300 flat, but still near six-year highs* Raiffeisen rallies after Q1 resultsBy Sudip Kar-GuptaLONDON, May 22 (Reuters) - Italian and Spanish stocks underperformed flat equity markets elsewhere in Europe on Thursday, as traders said c