forcedeth: Remove return from a void function

In a void function, it is not necessary to append a return statement in it.
Signed-off-by: NZhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/nvidia/forcedeth.c

@@ -3272,8 +3272,6 @@ static void nv_force_linkspeed(struct net_device *dev, int speed, int duplex)
 	pci_push(base);
 	writel(np->linkspeed, base + NvRegLinkSpeed);
 	pci_push(base);
-
-	return;
 }
 
 /**