scsi: efct: 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.

While at it, return the error code returned by dma_set_mask_and_coherent()
instead of -1.

[1]: https://lkml.org/lkml/2021/6/7/398

Link: https://lore.kernel.org/r/958bcb2a6e86344c14f38369e8e7079615a2b0e3.1641754613.git.christophe.jaillet@wanadoo.frReviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/elx/efct/efct_driver.c

@@ -541,13 +541,10 @@ efct_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pci_set_drvdata(pdev, efct);
 
-	if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)) != 0) {
-		dev_warn(&pdev->dev, "trying DMA_BIT_MASK(32)\n");
-		if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)) != 0) {
-			dev_err(&pdev->dev, "setting DMA_BIT_MASK failed\n");
-			rc = -1;
-			goto dma_mask_out;
-		}
+	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (rc) {
+		dev_err(&pdev->dev, "setting DMA_BIT_MASK failed\n");
+		goto dma_mask_out;
 	}
 
 	num_interrupts = efct_device_interrupts_required(efct);