Use volume driver specific exceptions
Use volume driver specific exceptions

Change generic use of exception.NovaException in the nova/volume directory
to specific exceptions. The exceptions used in this patch are:

 exception.VolumeBackendAPIException
 exception.InvalidInput
 exception.InvalidVolume
 exception.VolumeAtatched

Patch includes updates to the appropriate tests as well.

(cherry picked from cinder commit 3905a99)

Change-Id: I10407ff3f5babe64e88f445d3529269b7665ee16

citrix-openstack-build/oslo.versionedobjects,openstack/oslo.versionedobjects