scsi: lpfc: Fix NULL check before mempool_destroy is not needed

mempool_destroy has taken null pointer check into account. Remove the
redundant check.

Link: https://lore.kernel.org/r/20191026194712.GA22249@sauravSigned-off-by: Saurav Girepunje <saurav.girepunje@gmail.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_init.c

@@ -13464,8 +13464,7 @@ lpfc_sli4_oas_verify(struct lpfc_hba *phba)
 		phba->cfg_fof = 1;
 	} else {
 		phba->cfg_fof = 0;
-		if (phba->device_data_mem_pool)
-			mempool_destroy(phba->device_data_mem_pool);
+		mempool_destroy(phba->device_data_mem_pool);
 		phba->device_data_mem_pool = NULL;
 	}