staging: comedi: ni_daq_dio24: remove pcmcia_device private data

The private data, struct local_info_t, is not being used in the
driver. Remove it as well as the kzalloc/kfree.

Also, don't set the 'pcmcia_cur_dev' variable unless the pcmcia
probe is successful.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>