Devstack-GlusterFS-Plugin: Unsetting volume_prov_type in cinder.conf
Devstack-GlusterFS-Plugin: Unsetting volume_prov_type in cinder.conf

As the patch "Using 'fallocate' instead of 'dd' to create raw
volumes" [1] still in WIP, setting 'volume_prov_type' doesn't make
any sense and creates confusion too.

This patch modifies plugin code to not set 'volume_prov_type'.

[1] https://review.openstack.org/#/c/164527/

Change-Id: I5938d5ac833f0b18e41a8d4f9ad35860eaec8abd

stackforge/devstack-plugin-glusterfs,stackforge/devstack-plugin-glusterfs