staging: comedi: rtd520: remove RtdAdcFifoGet2 macro

This macro uses the 'devpriv' macro which relies on a local variable
having a specific name. It's also not used and the comment says it
does not work. Remove it.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/rtd520.c

@@ -406,10 +406,6 @@ struct rtdPrivate {
 
 /* Macros to access registers */
 
-/* Read two ADC data values (DOESN'T WORK) */
-#define RtdAdcFifoGet2(dev) \
-	readl(devpriv->las1+LAS1_ADC_FIFO)
-
 /* FIFO status */
 #define RtdFifoStatus(dev) \
 	readl(devpriv->las0+LAS0_ADC)