scsi: lpfc: fix potential buffer overflow.

This patch fixes a potential buffer overflow in lpfc_nvme_info_show().
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Acked-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_attr.c

@@ -181,7 +181,7 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 				wwn_to_u64(vport->fc_nodename.u.wwn),
 				phba->targetport->port_id);
 
-		len += snprintf(buf + len, PAGE_SIZE,
+		len += snprintf(buf + len, PAGE_SIZE - len,
 				"\nNVME Target: Statistics\n");
 		tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private;
 		len += snprintf(buf+len, PAGE_SIZE-len,
@@ -326,7 +326,7 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 	}
 	spin_unlock_irq(shost->host_lock);
 
-	len += snprintf(buf + len, PAGE_SIZE, "\nNVME Statistics\n");
+	len += snprintf(buf + len, PAGE_SIZE - len, "\nNVME Statistics\n");
 	len += snprintf(buf+len, PAGE_SIZE-len,
 			"LS: Xmt %016llx Cmpl %016llx\n",
 			phba->fc4NvmeLsRequests,