PCI: Speed up the Intel SMBus unhiding quirk

Speed up the Intel SMBus PCI quirk by avoiding tests which can only
fail. This also makes the compiled code significantly smaller when
using gcc 3.2/3.4. gcc 4.x appears to optimize the code by itself so
this change doesn't make a difference there.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>