staging: comedi: ni_pcidio: blank line issues

Fix the checkpatch.pl issue:
CHECK: Please use a blank line after function/struct/union/enum
declarations

Signed-off-by: Saber Rezvani <irsaber@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>