Vitol has bought at least 25 million barrels of Iraqi crude for September loading, making the world’s largest independent oil trader Iraq’s second-biggest buyer behind ADNOC as Baghdad pays steep discounts to keep barrels moving through the Strait of Hormuz. Iraq’s SOMO offered September crude at discounts of $15 to $20.80 per barrel to its official selling prices, according to a tender document reviewed by Reuters. Trading sources said some cargoes sold at even larger discounts. The discount buys something Iraq badly needs right…