Warren Buffett’s Berkshire Hathaway Inc. (NYSE:BRK.A) is acquiring the Duracell battery brand from Procter & Gamble Co (NYSE:PG) by letting go of  his shares at the world’s largest household products company.  The transaction regarding the deal, which is expected to complete by the second half of next year, will give P&G Buffett’s $4.7 billion worth…