drivers/net/r6040.c: remove exceptional & on function name

In this file, function names are otherwise used as pointers without &.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier f;
@@

f(...) { ... }

@@
identifier r.f;
@@

- &f
+ f
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/r6040.c

@@ -842,7 +842,7 @@ static int r6040_open(struct net_device *dev)
 	int ret;
 
 	/* Request IRQ and Register interrupt handler */
-	ret = request_irq(dev->irq, &r6040_interrupt,
+	ret = request_irq(dev->irq, r6040_interrupt,
 		IRQF_SHARED, dev->name, dev);
 	if (ret)
 		return ret;