scsi: lpfc: Fix sprintf() overflow in lpfc_display_fpin_wwpn()

This scnprintf() uses the wrong limit.  It should be
"LPFC_FPIN_WWPN_LINE_SZ - len" instead of LPFC_FPIN_WWPN_LINE_SZ.

Link: https://lore.kernel.org/r/20210916132251.GD25094@kili
Fixes: 428569e ("scsi: lpfc: Expand FPIN and RDF receive logging")
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_els.c

@@ -9387,7 +9387,7 @@ lpfc_display_fpin_wwpn(struct lpfc_hba *phba, __be64 *wwnlist, u32 cnt)
 		/* Extract the next WWPN from the payload */
 		wwn = *wwnlist++;
 		wwpn = be64_to_cpu(wwn);
-		len += scnprintf(buf + len, LPFC_FPIN_WWPN_LINE_SZ,
+		len += scnprintf(buf + len, LPFC_FPIN_WWPN_LINE_SZ - len,
 				 " %016llx", wwpn);
 
 		/* Log a message if we are on the last WWPN