staging: comedi: ni_pcidio: remove redundant mite disarm/reset

The mite_release_channel() will disarm and reset the mite channel.
Remove the redundant calls in ni_pcidio_release_di_mite_channel().

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>