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>

drivers/net/fddi/defxx.c

@@ -1070,11 +1070,10 @@ static int dfx_driver_init(struct net_device *dev, const char *print_name,
 					(PI_ALIGN_K_DESC_BLK - 1);
 	bp->kmalloced = top_v = dma_alloc_coherent(bp->bus_dev, alloc_size,
 						   &bp->kmalloced_dma,
-						   GFP_ATOMIC);
+						   GFP_ATOMIC | __GFP_ZERO);
 	if (top_v == NULL)
 		return DFX_K_FAILURE;
 
-	memset(top_v, 0, alloc_size);	/* zero out memory before continuing */
 	top_p = bp->kmalloced_dma;	/* get physical address of buffer */
 
 	/*