Fix a problem with for loops, copy semantics and async routines.

@proppy @bgrant0607 Fixes a bug introduced by https://github.com/GoogleCloudPlatform/kubernetes/commit/f91162cf789ac6742e4aa822a2542ab14454f909#diff-bf28da68f62a8df6e99e447c4351122dR637

Go lang for loop copy semantics and async routines are _not_ friends.