open_driver_key() is called by create_driver_key() and SetupDiOpenDevRegKey()
which depend on the failure path to detect the presence of the key.

This causes a lot of unnecessary errors being printed out.
Signed-off-by: Arkadiusz Hiler <ahiler@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>