labs: rename local vars: batch_for_windows
labs: rename local vars: batch_for_windows

Make local variables lowercase and some of them more descriptive.

Change-Id: Iee8c2e33593c124f86a4e99e8e35590bd3f96b9f

openstack/training-guides,Nabs007/training-guides,Nabs007/training-guides,openstack/training-guides,harrisonfeng/training-guides,Nabs007/training-guides,harrisonfeng/training-guides,harrisonfeng/training-guides