staging: comedi: addi_apci_3120: sample types are unsigned

Sample values in comedi are generally represented as unsigned values.
Change the element type of `ul_DmaBufferVirtual[2]` in `struct
addi_private` from `short *` to `unsigned short *` for consistency.
Note that several ADDI-DATA drivers use this struct from
"addi_common.h", but only the "addi_apci_3120" driver uses this member.
Also change the type of the `dma_buffer` parameter of
`v_APCI3120_InterruptDmaMoveBlock16bit()` from `short *` to `unsigned
short *`.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/addi-data/addi_common.h

@@ -133,7 +133,7 @@ struct addi_private {
 	unsigned short us_UseDma;	/*  To use Dma or not */
 	unsigned char b_DmaDoubleBuffer;	/*  we can use double buffering */
 	unsigned int ui_DmaActualBuffer;	/*  which buffer is used now */
-	short *ul_DmaBufferVirtual[2];	/*  pointers to begin of DMA buffer */
+	unsigned short *ul_DmaBufferVirtual[2];	/*  pointers to DMA buffer */
 	unsigned int ul_DmaBufferHw[2];	/*  hw address of DMA buff */
 	unsigned int ui_DmaBufferSize[2];	/*  size of dma buffer in bytes */
 	unsigned int ui_DmaBufferUsesize[2];	/*  which size we may now used for transfer */

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c

@@ -1391,7 +1391,7 @@ static int i_APCI3120_CommandAnalogInput(struct comedi_device *dev,
  */
 static void v_APCI3120_InterruptDmaMoveBlock16bit(struct comedi_device *dev,
 						  struct comedi_subdevice *s,
-						  short *dma_buffer,
+						  unsigned short *dma_buffer,
 						  unsigned int num_samples)
 {
 	struct addi_private *devpriv = dev->private;