The Oracle of Omaha now owns more than 3% of a powerhouse restaurant brand.Another quarter, another Apple (AAPL 0.59%) sale from Warren Buffett. The legendary investor sold a massive chunk of Apple stock yet again in the third quarter, estimated to be worth more than $20 billion, or 100 million shares. Berkshire Hathaway -- the company Buffett controls -- still owns $70 billion of Apple stock, but it is now a much smaller position than at the start of the year.Why is Buffett selling? This article will get i ...