fungible driver should be using volume_utils to upload volume as an image

[Brian Rosmaita]

Noticed this in master (Dalmatian development branch). A few cycles back, volume_utils.upload_volume() was introduced as a wrapper for image_utils.upload_volume(); it does some manipulation of volume glance metadata before calling the image_utils function.

The fungible driver is using image_utils:
https://opendev.org/openstack/cinder/src/commit/79629c346e001e88a03a63f3a713b7af6ee8193c/cinder/volume/drivers/fungible/driver.py

This should be corrected, because fungible volumes uploaded as images will be missing the base image ref, among other things. (And, of course, they'll also miss out on any future enhancements to the volume_utils function.)