Two billionaires are fighting over the financials of a massive truck stop chain — and now the feds are involved. According to an explosive Wednesday report from Bloomberg, a contentious feud between Cleveland Browns owner Jimmy Haslam and celebrity billionaire philanthropist Warren Buffett has captured the attention of federal prosecutors in Manhattan. Haslam and Buffett have been locked in a legal battle over a number of issues stemming from the sale of ownership in Pilot Travel Centers, a truck stop chain owned by the Haslam family, to Buffett’s Berkshire Hathway, which was originally annou…