sky2: crash on remove

Fix off-by one in remove logic that just got introduced.

Signed-off-by: Stephen Hemminger <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/sky2.c

···
 	del_timer_sync(&hw->watchdog_timer);
 	cancel_work_sync(&hw->restart_work);
 
-	for (i = hw->ports; i >= 0; --i)
+	for (i = hw->ports-1; i >= 0; --i)
 		unregister_netdev(hw->dev[i]);
 
 	sky2_write32(hw, B0_IMSK, 0);
···
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
 
-	for (i = hw->ports; i >= 0; --i)
+	for (i = hw->ports-1; i >= 0; --i)
 		free_netdev(hw->dev[i]);
 
 	iounmap(hw->regs);