drivers/net/: remove write-only "last_dev"

This patch removes write-only global "last_dev" variables from the
following drivers:
- a2065.c
- declance.c
- sunlance.c

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/a2065.c

@@ -475,16 +475,12 @@ static irqreturn_t lance_interrupt (int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-struct net_device *last_dev;
-
 static int lance_open (struct net_device *dev)
 {
 	struct lance_private *lp = netdev_priv(dev);
 	volatile struct lance_regs *ll = lp->ll;
 	int ret;
 
-	last_dev = dev;
-
 	/* Stop the Lance */
 	ll->rap = LE_CSR0;
 	ll->rdp = LE_C0_STOP;