Staging: comedi: ni_mio_common.c: Added blank line after declarations

Added blank line after declarations.

Signed-off-by: Arash Fotouhi <arash@arashfotouhi.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>