pcmcia: fix error handling in cm4000_cs.c

In the original code we used -ENODEV as the number of bytes to
copy_to_user() and we didn't release the locks.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Harald Welte <laforge@gnumonks.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>