The 'counter_number' in these functions is the comedi channel number from the
chanspec. The comedi core validates the chanspec before calling the driver
functions. Remove the unnecessary checks.
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>