[PATCH] mmconfig: fix unreachable_devices()

Currently, unreachable_devices() compares value of mmconfig and value
of conf1. But it doesn't check the device is reachable or not.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>