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/faraday/ftmac100.c b/drivers/net/ethernet/faraday/ftmac100.c
index 4658f4c..8be5b40 100644
--- a/drivers/net/ethernet/faraday/ftmac100.c
+++ b/drivers/net/ethernet/faraday/ftmac100.c
@@ -732,10 +732,10 @@
 {
 	int i;
 
-	priv->descs = dma_alloc_coherent(priv->dev,
-					 sizeof(struct ftmac100_descs),
-					 &priv->descs_dma_addr,
-					 GFP_KERNEL | __GFP_ZERO);
+	priv->descs = dma_zalloc_coherent(priv->dev,
+					  sizeof(struct ftmac100_descs),
+					  &priv->descs_dma_addr,
+					  GFP_KERNEL);
 	if (!priv->descs)
 		return -ENOMEM;