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/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index c238f98..24748e8 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -204,25 +204,23 @@
 	lp->tx_bd_v = dma_alloc_coherent(ndev->dev.parent,
 					 sizeof(*lp->tx_bd_v) * TX_BD_NUM,
 					 &lp->tx_bd_p,
-					 GFP_KERNEL);
+					 GFP_KERNEL | __GFP_ZERO);
 	if (!lp->tx_bd_v)
 		goto out;
 
 	lp->rx_bd_v = dma_alloc_coherent(ndev->dev.parent,
 					 sizeof(*lp->rx_bd_v) * RX_BD_NUM,
 					 &lp->rx_bd_p,
-					 GFP_KERNEL);
+					 GFP_KERNEL | __GFP_ZERO);
 	if (!lp->rx_bd_v)
 		goto out;
 
-	memset(lp->tx_bd_v, 0, sizeof(*lp->tx_bd_v) * TX_BD_NUM);
 	for (i = 0; i < TX_BD_NUM; i++) {
 		lp->tx_bd_v[i].next = lp->tx_bd_p +
 				      sizeof(*lp->tx_bd_v) *
 				      ((i + 1) % TX_BD_NUM);
 	}
 
-	memset(lp->rx_bd_v, 0, sizeof(*lp->rx_bd_v) * RX_BD_NUM);
 	for (i = 0; i < RX_BD_NUM; i++) {
 		lp->rx_bd_v[i].next = lp->rx_bd_p +
 				      sizeof(*lp->rx_bd_v) *