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: 428569e6

 ("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>