staging: comedi: remove this_board macro in the dt2811 driver

The 'this_board' macro depends on having a local variable with
a magic name. The CodingStyle document suggests not doing this
to avoid confusion. Remove the macro and use the comedi_board()
inline helper to get the dev->board_ptr information.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt2811.c

@@ -211,8 +211,6 @@ struct dt2811_board {
 	const struct comedi_lrange *unip_5;
 };
 
-#define this_board ((const struct dt2811_board *)dev->board_ptr)
-
 enum { card_2811_pgh, card_2811_pgl };
 
 struct dt2811_private {
@@ -404,6 +402,7 @@ static int dt2811_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	/* unsigned long irqs; */
 	/* long flags; */
 
+	const struct dt2811_board *board = comedi_board(dev);
 	int ret;
 	struct comedi_subdevice *s;
 	unsigned long iobase;
@@ -418,7 +417,7 @@ static int dt2811_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	}
 
 	dev->iobase = iobase;
-	dev->board_name = this_board->name;
+	dev->board_name = board->name;
 
 #if 0
 	outb(0, dev->iobase + DT2811_ADCSR);
@@ -527,13 +526,13 @@ static int dt2811_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	switch (it->options[3]) {
 	case 0:
 	default:
-		s->range_table = this_board->bip_5;
+		s->range_table = board->bip_5;
 		break;
 	case 1:
-		s->range_table = this_board->bip_2_5;
+		s->range_table = board->bip_2_5;
 		break;
 	case 2:
-		s->range_table = this_board->unip_5;
+		s->range_table = board->unip_5;
 		break;
 	}