scsi: fix off-by-one LUN check in scsi_scan_host_selected()

The Scsi_Host structure max_lun field is the maximum allowed LUN plus 1. So
a LUN value is invalid if >= max_lun.

Signed-off-by: Mark Knibbs <markk@clara.co.uk>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 619e68d..b1aa164 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1727,7 +1727,7 @@
 
 	if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
 	    ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
-	    ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
+	    ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun)))
 		return -EINVAL;
 
 	mutex_lock(&shost->scan_mutex);