staging: comedi: das16: remove unused static const variable

This variable is not used in the driver. Remove it.
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>

drivers/staging/comedi/drivers/das16.c

@@ -174,9 +174,6 @@ www.measurementcomputing.com
 
 */
 
-/*  size in bytes of a sample from board */
-static const int sample_size = 2;
-
 #define DAS16_TRIG		0
 #define DAS16_AI_LSB		0
 #define DAS16_AI_MSB		1