Fix for h/w update bug - constant / scoping error
Merge pull request #126 from Raajeev/pull-req-release-mesa-1.6-master-6e2521c71d183c9549d90de170f82ddc3a222363

Fix for h/w update bug - constant / scoping error [1/1]
Make unique_name a little more robust in the face of directory
ordering.

Also add a unique_device method.