bring back
commit 
d21e9daa63e009ce5b87bbcaa6d11ce48e07bbbe
("[SCSI] zfcp: Dont use 0 to indicate invalid LUN in rec trace")
which was lost with
commit 
ae0904f60fab7cb20c48d32eefdd735e478b91fb
("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.")
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: ae0904f60fab ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.")
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
        if (sdev) {
                rec->lun_status = atomic_read(&sdev_to_zfcp(sdev)->status);
                rec->lun = zfcp_scsi_dev_lun(sdev);
-       }
+       } else
+               rec->lun = ZFCP_DBF_INVALID_LUN;
 }
 
 /**