fix the scsi device name order on guest vm. the guest vm scsi device name order is associated with following libvirt xml config: - address controller slot, - address unit, - target dev order. see the rule details on jira.
fix the scsi device name order on guest vm.
the guest vm scsi device name order is associated with following
libvirt xml config:
- address controller slot,
- address unit,
- target dev order.
see the rule details on jira.

so when start/reboot vm:
- first set the index of controller to 0 for all scsi volumes.
- then make sure the volume whose unit is 0 is the first or non-exsitent.
- finally reverse scsi volume device names.

resolve ZSTAC-9641

live4thee/zstack-utility,zstackio/zstack-utility,zstackorg/zstack-utility,zstackorg/zstack-utility,zstackio/zstack-utility,zstackio/zstack-utility,live4thee/zstack-utility,zstackorg/zstack-utility,live4thee/zstack-utility