hinic: 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.

Simplify code and remove some dead code accordingly.

[1]: https://lkml.org/lkml/2021/6/7/398Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/23541c28df8d0dcd3663b5dbe0f76af71e70e9cc.1641743855.git.christophe.jaillet@wanadoo.frSigned-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/huawei/hinic/hinic_main.c

@@ -1392,12 +1392,8 @@ static int hinic_probe(struct pci_dev *pdev,
 
 	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 	if (err) {
-		dev_warn(&pdev->dev, "Couldn't set 64-bit DMA mask\n");
-		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
-		if (err) {
-			dev_err(&pdev->dev, "Failed to set DMA mask\n");
-			goto err_dma_mask;
-		}
+		dev_err(&pdev->dev, "Failed to set DMA mask\n");
+		goto err_dma_mask;
 	}
 
 	err = nic_dev_init(pdev);