pcmcia: dtl1_cs: fix pcmcia_loop_config logic

pcmcia_loop_config returns 0 on success.

[wsa: added '< 0' for better readability]

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>