3c59x: Ensure to apply the expires time

In commit 5b6490de ("3c59x: Use setup_timer()") Amitoj
removed add_timer which sets up the epires timer.  In this patch
the behavior is restore but it uses mod_timer which is a bit more
compact.
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/3com/3c59x.c

@@ -1602,7 +1602,7 @@ vortex_up(struct net_device *dev)
 	}
 
 	setup_timer(&vp->timer, vortex_timer, (unsigned long)dev);
-	vp->timer.expires = RUN_AT(media_tbl[dev->if_port].wait);
+	mod_timer(&vp->timer, RUN_AT(media_tbl[dev->if_port].wait));
 	setup_timer(&vp->rx_oom_timer, rx_oom_timer, (unsigned long)dev);
 
 	if (vortex_debug > 1)