scsi: lpfc: Remove unnecessary null ndlp check in lpfc_sli_prep_wqe()

Smatch had the following warning:

drivers/scsi/lpfc/lpfc_sli.c:22305 lpfc_sli_prep_wqe() error: we previously assumed 'ndlp' could be null (see line 22298)

Remove the unnecessary null check.

Link: https://lore.kernel.org/r/20220426181315.8990-1-jsmart2021@gmail.com
Fixes: d51cf5bd

 ("scsi: lpfc: Fix field overload in lpfc_iocbq data structure")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>