Chick-fil-A's oldest restaurant, which opened in an Atlanta mall 56 years ago, is closing. The restaurant, located in the food court of Greenbriar Mall to the southwest of the city, is set to shut for good at 4 p.m. on Saturday, The Atlanta Journal-Constitution reported. Printed-out signs posted at the location don't give reasons for the closure. Chick-fil-A founder S. Truett Cathy opened the restaurant in 1967 in what was one of the first indoor malls in the Southeast. He'd previously set up a diner in Atlanta called The Dwarf Grill, later renamed The Dwarf House, with his brother Ben....