The error codes:
 - DID_TARGET_FAILURE
 - DID_NEXUS_FAILURE
 - DID_ALLOC_FAILURE
 - DID_MEDIUM_ERROR
are internal to the SCSI layer. Drivers must not use them because:
 1. They are not propagated upwards, so SG IO/passthrough users will not
    see an error and think a command was successful.
    xen-scsiback will never see this error and should not try to send it.
 2. There is no handling for them in scsi_decide_disposition() so if
    xen-scsifront were to return the error to the SCSI midlayer then it
    kicks off the error handler which is definitely not what we want.
Remove the use from xen-scsifront/back.
Link: https://lore.kernel.org/r/20220812010027.8251-2-michael.christie@oracle.com
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
                return DID_TRANSPORT_DISRUPTED;
        case XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST:
                return DID_TRANSPORT_FAILFAST;
-       case XEN_VSCSIIF_RSLT_HOST_TARGET_FAILURE:
-               return DID_TARGET_FAILURE;
-       case XEN_VSCSIIF_RSLT_HOST_NEXUS_FAILURE:
-               return DID_NEXUS_FAILURE;
-       case XEN_VSCSIIF_RSLT_HOST_ALLOC_FAILURE:
-               return DID_ALLOC_FAILURE;
-       case XEN_VSCSIIF_RSLT_HOST_MEDIUM_ERROR:
-               return DID_MEDIUM_ERROR;
        case XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL:
                return DID_TRANSPORT_MARGINAL;
        default:
 
        case DID_TRANSPORT_FAILFAST:
                host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST;
                break;
-       case DID_TARGET_FAILURE:
-               host_status = XEN_VSCSIIF_RSLT_HOST_TARGET_FAILURE;
-               break;
-       case DID_NEXUS_FAILURE:
-               host_status = XEN_VSCSIIF_RSLT_HOST_NEXUS_FAILURE;
-               break;
-       case DID_ALLOC_FAILURE:
-               host_status = XEN_VSCSIIF_RSLT_HOST_ALLOC_FAILURE;
-               break;
-       case DID_MEDIUM_ERROR:
-               host_status = XEN_VSCSIIF_RSLT_HOST_MEDIUM_ERROR;
-               break;
        case DID_TRANSPORT_MARGINAL:
                host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL;
                break;