patch be8a1f7c in mainline.

Turns out we don't actually check the status to see if there was a
device out there to talk to, just if we had a timeout when doing so.

Add the proper check, so we don't falsly think there are devices
on the bus that are not there, etc.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>