staging: comedi: ni_pcidio: remove n_ndio_boards macro

This macro is not used in the driver. Remove it.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_pcidio.c

@@ -304,7 +304,6 @@ static const struct nidio_board nidio_boards[] = {
 	},
 };
 
-#define n_nidio_boards ARRAY_SIZE(nidio_boards)
 #define this_board ((const struct nidio_board *)dev->board_ptr)
 
 struct nidio96_private {