isa_register_driver() returns an error if no device is found
and it's no fatal error for the drivers with pnp support.
Signed-off-by: NRene Herman <rene.herman@gmail.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>