staging: comedi: drivers: cb_pcimdda: fix warning on quoted string split across lines.

Checkpatch.pl complains about "quoted string split across lines" for
string in MODULE_DESCRIPTION().

Put string on only one line.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>