net: natsemi: Add initialized eth_device structure

natsemi driver does not have write_hwaddr function.
However, eth stuff executes write_hwaddr function
because eth_device structure has not been initialized.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
CC: Ben Warren <biggerbadderben@gmail.com>

drivers/net/natsemi.c

@@ -321,6 +321,11 @@ natsemi_initialize(bd_t * bis)
 		}
 
 		dev = (struct eth_device *) malloc(sizeof *dev);
+		if (!dev) {
+			printf("natsemi: Can not allocate memory\n");
+			break;
+		}
+		memset(dev, 0, sizeof(*dev));
 
 		sprintf(dev->name, "dp83815#%d", card_number);
 		dev->iobase = bus_to_phys(iobase);