autotest/factoryVerify: fix variable binding issue

In conde refine ( http://codereview.chromium.org/6596018 ),
the module name was changed and caused conflicts with variable name.

BUG=chrome-os-partner:2611
TEST=verified pylint and grep -Ril 'gpio = gpio', grep -Ril 'vblock = vblock'.

Change-Id: I6d530435ccc48869edd5fbfc39ece367507c12ca

Review URL: http://codereview.chromium.org/6633013
1 file changed