scsi: xen-scsiback: Use DID_ERROR instead of DRIVER_ERROR

scsi: xen-scsiback: Use DID_ERROR instead of DRIVER_ERROR

DRIVER_ERROR was supposed to signal an error generated by the driver, which
xen-scsiback arguably isn't. Also the driver bytes don't have a detailed
error recovery, so we should rather return DID_ERROR instead of
DRIVER_ERROR.

Link: https://lore.kernel.org/r/20210427083046.31620-13-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>