scsi: lpfc: Make lpfc_defer_acc_rsp static

Fix sparse warning:

drivers/scsi/lpfc/lpfc_nportdisc.c:344:1: warning:
 symbol 'lpfc_defer_acc_rsp' was not declared. Should it be static?

Link: https://lore.kernel.org/r/20200107014956.41748-1-yuehaibing@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>