octeon_ep: delete unnecessary NULL check

vfree(NULL) is safe. NULL check before vfree() is not needed.
Delete them to simplify the code.

Signed-off-by: Ziyang Xuan <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/marvell/octeon_ep/octep_main.c

···
 	dev_info(&oct->pdev->dev, "Cleaning up Octeon Device ...\n");
 
 	for (i = 0; i < OCTEP_MAX_VF; i++) {
-		if (oct->mbox[i])
-			vfree(oct->mbox[i]);
+		vfree(oct->mbox[i]);
 		oct->mbox[i] = NULL;
 	}
 

drivers/net/ethernet/marvell/octeon_ep/octep_rx.c

···
 
 	octep_oq_free_ring_buffers(oq);
 
-	if (oq->buff_info)
-		vfree(oq->buff_info);
+	vfree(oq->buff_info);
 
 	if (oq->desc_ring)
 		dma_free_coherent(oq->dev,

drivers/net/ethernet/marvell/octeon_ep/octep_tx.c

···
 
 	desc_ring_size = OCTEP_IQ_DESC_SIZE * CFG_GET_IQ_NUM_DESC(oct->conf);
 
-	if (iq->buff_info)
-		vfree(iq->buff_info);
+	vfree(iq->buff_info);
 
 	if (iq->desc_ring)
 		dma_free_coherent(iq->dev, desc_ring_size,