WASHINGTON (Reuters) – U.S. farmers who have been holding out for higher prices for their corn may finally sell their grain below target levels in the next few weeks as a government report released on Friday underscores the huge supplies left in storage bins around the country, analysts said. The U.S. Agriculture Department said that farmers still had 2.841 billion bushels of corn in their storage bins as of June 1, the fifth most ever for that time period. It was the highest June 1 on-farm corn