[coreboot] Patch merged into coreboot/master: 82568c6 libpayload: Add check for failure in usb_attach_device()

the following patch was just integrated into master:
commit 82568c60960b61ff510b1ba4ef24a688e1a900ae
Author: Nico Huber 
Date:   Thu Jun 21 11:21:23 2012 +0200

libpayload: Add check for failure in usb_attach_device()

This adds a simple check if a device is really configured before
    returning it's address to the usb hub driver who wants to attach it.

Change-Id: I6fea140217c3e7468cc48ef7c3cbf2be8d11f47a
    Signed-off-by: Nico Huber

See http://review.coreboot.org/1131 for details.

-gerrit