Fix regression in Cinder volume type creation

The local-vars cleanup (Iedeafa15def1fa26d4ddcbc5f670129f66e38b9d)
spanned (and missed) this fix (Ib35ffc09f6582354010ac8ca35da581ea508877a)
for volume type creation.

Change-Id: I2b95cbc946727d7708283eca0c07ba1eaddf5db8
Merge "Fix regression in Cinder volume type creation"