Update to new volman driver path API
Update to new volman driver path API

[#118324851](https://www.pivotaltracker.com/story/show/118324851)

Signed-off-by: Julian Hjortshoj <a84af1ff40fcfa3bc4844358f827e17a8b38c426@emc.com>

cloudfoundry-incubator/inigo