drivers:net: dma_alloc_coherent: use __GFP_ZERO instead of memset(, 0)

Reduce the number of calls required to alloc
a zeroed block of memory.

Trivially reduces overall object size.

Other changes around these removals
o Neaten call argument alignment
o Remove an unnecessary OOM message after dma_alloc_coherent failure
o Remove unnecessary gfp_t stack variable

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c
index 3ae4c7f..339bb32 100644
--- a/drivers/net/ethernet/marvell/pxa168_eth.c
+++ b/drivers/net/ethernet/marvell/pxa168_eth.c
@@ -584,12 +584,14 @@
 	 */
 	if (pep->htpr == NULL) {
 		pep->htpr = dma_alloc_coherent(pep->dev->dev.parent,
-					      HASH_ADDR_TABLE_SIZE,
-					      &pep->htpr_dma, GFP_KERNEL);
+					       HASH_ADDR_TABLE_SIZE,
+					       &pep->htpr_dma,
+					       GFP_KERNEL | __GFP_ZERO);
 		if (pep->htpr == NULL)
 			return -ENOMEM;
+	} else {
+		memset(pep->htpr, 0, HASH_ADDR_TABLE_SIZE);
 	}
-	memset(pep->htpr, 0, HASH_ADDR_TABLE_SIZE);
 	wrl(pep, HTPR, pep->htpr_dma);
 	return 0;
 }
@@ -1023,11 +1025,11 @@
 	size = pep->rx_ring_size * sizeof(struct rx_desc);
 	pep->rx_desc_area_size = size;
 	pep->p_rx_desc_area = dma_alloc_coherent(pep->dev->dev.parent, size,
-						&pep->rx_desc_dma, GFP_KERNEL);
+						 &pep->rx_desc_dma,
+						 GFP_KERNEL | __GFP_ZERO);
 	if (!pep->p_rx_desc_area)
 		goto out;
 
-	memset((void *)pep->p_rx_desc_area, 0, size);
 	/* initialize the next_desc_ptr links in the Rx descriptors ring */
 	p_rx_desc = pep->p_rx_desc_area;
 	for (i = 0; i < rx_desc_num; i++) {
@@ -1084,10 +1086,10 @@
 	size = pep->tx_ring_size * sizeof(struct tx_desc);
 	pep->tx_desc_area_size = size;
 	pep->p_tx_desc_area = dma_alloc_coherent(pep->dev->dev.parent, size,
-						&pep->tx_desc_dma, GFP_KERNEL);
+						 &pep->tx_desc_dma,
+						 GFP_KERNEL | __GFP_ZERO);
 	if (!pep->p_tx_desc_area)
 		goto out;
-	memset((void *)pep->p_tx_desc_area, 0, pep->tx_desc_area_size);
 	/* Initialize the next_desc_ptr links in the Tx descriptors ring */
 	p_tx_desc = pep->p_tx_desc_area;
 	for (i = 0; i < tx_desc_num; i++) {