cross-tree: phase out dma_zalloc_coherent()

We already need to zero out memory for dma_alloc_coherent(), as such
using dma_zalloc_coherent() is superflous. Phase it out.

This change was generated with the following Coccinelle SmPL patch:

@ replace_dma_zalloc_coherent @
expression dev, size, data, handle, flags;
@@

-dma_zalloc_coherent(dev, size, handle, flags)
+dma_alloc_coherent(dev, size, handle, flags)

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
[hch: re-ran the script on the latest tree]
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/net/ethernet/atheros/alx/main.c

@@ -660,10 +660,9 @@ static int alx_alloc_rings(struct alx_priv *alx)
 			    alx->num_txq +
 			    sizeof(struct alx_rrd) * alx->rx_ringsz +
 			    sizeof(struct alx_rfd) * alx->rx_ringsz;
-	alx->descmem.virt = dma_zalloc_coherent(&alx->hw.pdev->dev,
-						alx->descmem.size,
-						&alx->descmem.dma,
-						GFP_KERNEL);
+	alx->descmem.virt = dma_alloc_coherent(&alx->hw.pdev->dev,
+					       alx->descmem.size,
+					       &alx->descmem.dma, GFP_KERNEL);
 	if (!alx->descmem.virt)
 		return -ENOMEM;