pcmcia_loop_config returns 0 on success.

[wsa: added '< 0' for better readability]
Signed-off-by: NPhilipp Zabel <philipp.zabel@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>