staging: comedi: das800: rename {enable,disable}_das800

For aesthetic reasons, rename these functions to match the namespace
of the rest of the driver. Also, remove the unnecessary comments.

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