drivers:net: Convert dma_alloc_coherent(...__GFP_ZERO) to dma_zalloc_coherent

__GFP_ZERO is an uncommon flag and perhaps is better
not used.  static inline dma_zalloc_coherent exists
so convert the uses of dma_alloc_coherent with __GFP_ZERO
to the more common kernel style with zalloc.

Remove memset from the static inline dma_zalloc_coherent
and add just one use of __GFP_ZERO instead.

Trivially reduces the size of the existing uses of
dma_zalloc_coherent.

Realign arguments as appropriate.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index 190219e..98b6870 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -948,8 +948,7 @@
 
 	/* allocate rx dma ring */
 	size = priv->rx_ring_size * sizeof(struct bcm_enet_desc);
-	p = dma_alloc_coherent(kdev, size, &priv->rx_desc_dma,
-			       GFP_KERNEL | __GFP_ZERO);
+	p = dma_zalloc_coherent(kdev, size, &priv->rx_desc_dma, GFP_KERNEL);
 	if (!p) {
 		ret = -ENOMEM;
 		goto out_freeirq_tx;
@@ -960,8 +959,7 @@
 
 	/* allocate tx dma ring */
 	size = priv->tx_ring_size * sizeof(struct bcm_enet_desc);
-	p = dma_alloc_coherent(kdev, size, &priv->tx_desc_dma,
-			       GFP_KERNEL | __GFP_ZERO);
+	p = dma_zalloc_coherent(kdev, size, &priv->tx_desc_dma, GFP_KERNEL);
 	if (!p) {
 		ret = -ENOMEM;
 		goto out_free_rx_ring;