scsi: lpfc: Replace outdated strncpy() with strscpy()

The kernel test robot pointed out non-NULL terminated string possibilities
when using strncpy() in lpfc_xcvr_data_show() routine.  Although we
manually set the NULL character after strncpy(), strncpy() usage is
outdated.

Replace all strncpy() usages with the preferred strscpy() API.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>