scsi: lpfc: Remove unneeded result variable

Return the value from lpfc_issue_reg_vfi() directly instead of storing it
in another redundant variable.

Link: https://lore.kernel.org/r/20220824075123.221316-1-ye.xingchen@zte.com.cn


Reported-by: Zeal Robot <zealci@zte.com.cn>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>