From: Thomas Gleixner <tglx@linutronix.de>

Simple fix to make pci_enable/disable symetric and avoid the warning on
module unload.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>