bnx2x: Remove useless DMA-32 fallback configuration

As stated in [1], dma_set_mask() with a 64-bit mask never fails if
dev->dma_mask is non-NULL.
So, if it fails, the 32 bits case will also fail for the same reason.

Moreover, dma_set_mask_and_coherent() returns 0 or -EIO, so the return
code of the function can be used directly.

Finally, inline bnx2x_set_coherency_mask() because it is now only a wrapper
for a single dma_set_mask_and_coherent() call.

Simplify code and remove some dead code accordingly.

[1]: https://lkml.org/lkml/2021/6/7/398Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/29608a525876afddceabf8f11b2ba606da8748fc.1641730747.git.christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c

@@ -13044,19 +13044,6 @@ static const struct net_device_ops bnx2x_netdev_ops = {
 	.ndo_features_check	= bnx2x_features_check,
 };
 
-static int bnx2x_set_coherency_mask(struct bnx2x *bp)
-{
-	struct device *dev = &bp->pdev->dev;
-
-	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)) != 0 &&
-	    dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)) != 0) {
-		dev_err(dev, "System does not support DMA, aborting\n");
-		return -EIO;
-	}
-
-	return 0;
-}
-
 static void bnx2x_disable_pcie_error_reporting(struct bnx2x *bp)
 {
 	if (bp->flags & AER_ENABLED) {
@@ -13134,9 +13121,11 @@ static int bnx2x_init_dev(struct bnx2x *bp, struct pci_dev *pdev,
 		goto err_out_release;
 	}
 
-	rc = bnx2x_set_coherency_mask(bp);
-	if (rc)
+	rc = dma_set_mask_and_coherent(&bp->pdev->dev, DMA_BIT_MASK(64));
+	if (rc) {
+		dev_err(&bp->pdev->dev, "System does not support DMA, aborting\n");
 		goto err_out_release;
+	}
 
 	dev->mem_start = pci_resource_start(pdev, 0);
 	dev->base_addr = dev->mem_start;