ravb: use pdev rather than ndev for error messages

This corrects what appear to be typos, making the code consistent with
itself, and allowing meaningful prefixes to be displayed with the errors in
question.

Before:
 (null): failed to initialize MDIO
 (null): Cannot allocate desc base address table (size 176 bytes)

After:
ravb e6800000.ethernet: failed to initialize MDIO
ravb e6800000.ethernet: Cannot allocate desc base address table (size 176 bytes)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/ravb_main.c

@@ -1765,7 +1765,7 @@ static int ravb_probe(struct platform_device *pdev)
 	priv->desc_bat = dma_alloc_coherent(ndev->dev.parent, priv->desc_bat_size,
 					    &priv->desc_bat_dma, GFP_KERNEL);
 	if (!priv->desc_bat) {
-		dev_err(&ndev->dev,
+		dev_err(&pdev->dev,
 			"Cannot allocate desc base address table (size %d bytes)\n",
 			priv->desc_bat_size);
 		error = -ENOMEM;
@@ -1792,7 +1792,7 @@ static int ravb_probe(struct platform_device *pdev)
 	/* MDIO bus init */
 	error = ravb_mdio_init(priv);
 	if (error) {
-		dev_err(&ndev->dev, "failed to initialize MDIO\n");
+		dev_err(&pdev->dev, "failed to initialize MDIO\n");
 		goto out_dma_free;
 	}