images dir already exists, we just need to set it

src/pylorax/__init__.py

@@ -468,10 +468,9 @@ class Lorax(BaseLoraxClass):
                                                    "EFI/BOOT")
             os.makedirs(self.outputtree.efibootdir)
 
-            # create imgdir
+            # set imgdir
             self.outputtree.imgdir = joinpaths(self.outputtree.root,
                                                "images")
-            os.makedirs(self.outputtree.imgdir)
 
             kernel = i.kernels[0]
             initrd = i.initrds[0]