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>

drivers/net/fddi/defxx.c

@@ -1068,9 +1068,9 @@ static int dfx_driver_init(struct net_device *dev, const char *print_name,
 #endif
 					sizeof(PI_CONSUMER_BLOCK) +
 					(PI_ALIGN_K_DESC_BLK - 1);
-	bp->kmalloced = top_v = dma_alloc_coherent(bp->bus_dev, alloc_size,
-						   &bp->kmalloced_dma,
-						   GFP_ATOMIC | __GFP_ZERO);
+	bp->kmalloced = top_v = dma_zalloc_coherent(bp->bus_dev, alloc_size,
+						    &bp->kmalloced_dma,
+						    GFP_ATOMIC);
 	if (top_v == NULL)
 		return DFX_K_FAILURE;