Westfield Montgomery mall is undergoing a bit of spring cleaning, with two store closings in the past few weeks and another on the way. The Michael Kors store, whose parent company is reducing its brick-and-mortar footprint, went dark at the end of March. The Amazon 4-Star store is also gone, after the e-commerce behemoth pulled the plug on this short-lived concept. And Patrizia Luca, the locally owned boutique that has moved around the mall these past seven years, will soon be closing for good.