[ARCNET]: Fix crash in 2.6.8.1

>  I am trying to upgrade my labtop to 2.6.8.1. I have ArcNet COM20020
> PCMCIA card. After editing /etc/pcmcia/config to make it know about the
> module, it finds the com20020 with no problems but as soon as I try to
> start the network device the ifconfig process crashes.
:
> I fixed it by changing
> 	lp->hw.open(dev);
> to
> 	if(lp->hw.open) {
> 		lp->hw.open(dev);
> 	}
Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/arcnet/arcnet.c

@@ -401,6 +401,7 @@ static int arcnet_open(struct net_device *dev)
 	lp->rfc1201.sequence = 1;
 
 	/* bring up the hardware driver */
+	if (lp->hw.open)
 		lp->hw.open(dev);
 
 	if (dev->dev_addr[0] == 0)