Remove mountpoint from parse_volume_info
Remove mountpoint from parse_volume_info

Related to blueprint xenapi-volume-drivers

parse_volume_info method did too many things. It was checking the
connection_data for iscsi information, and also checked the mountpoint.
This change extracts the mountpoint conversion, and performs that check
earlier in the volume attach process.

Change-Id: I7c26e813319f6d9de287782ad188b22804d032a9

n0ano/ganttclient