In the latest sign of the revolving door between Wall Street and Washington, Eric Holder is returning to the corporate law firm where he worked before becoming head of the Justice Department. Holder was a partner at the firm Covington & Burling for eight years before becoming attorney general, representing clients including UBS and the fruit giant Chiquita. The law firm’s client list has included many of the big banks Holder failed to criminally prosecute as attorney general for their role in the financial crisis, including Bank of America, JPMorgan Chase, Wells Fargo and Citigroup. The law firm had reportedly kept a corner office vacant for Holder.