rtl8139too.c: Fix missing pci_disable_dev

Simple fix to make pci_enable/disable symetric and avoid the warning on module unload.

diff -urN --exclude='*~' 2.6.9-mm1-U10/drivers/net/8139too.c 2.6.9-mm1-U10.work/drivers/net/8139too.c
--- 2.6.9-mm1-U10/drivers/net/8139too.c 2004-10-22 19:10:44.000000000
+0200
+++ 2.6.9-mm1-U10.work/drivers/net/8139too.c 2004-10-22
21:52:19.000000000 +0200
@@ -749,7 +749,7 @@
pci_release_regions (pdev);

free_netdev(dev);
-
+ pci_disable_device(pdev);
pci_set_drvdata (pdev, NULL);
}