A federal appeals court on Wednesday revived Ohio’s lawsuit accusing Freddie Mac of defrauding the state’s $87.3 billion public pension fund by hiding its exposure to subprime and other risky mortgages prior to the 2007-09 financial crisis. The 6th U.S. Circuit Court of Appeals said a lower court judge erred in finding that the Ohio Public Employees Retirement System (OPERS) did not plausibly …