staging: comedi: ni_atmio: fix build errors

The following commits introduced a couple build errors in this driver
due to the removal of some macros in ni_stc.h.

commit: f5a1d92 "staging: comedi: ni_stc.h: remove n_ni_boards macro"
commit: 6293e35 "staging: comedi: ni_stc.h: remove boardtype macro"

The n_ni_boards macro is an open coded version of ARRAY_SIZE.

The boardtype macro is removed in favor of using the comedi_board()
helper and accessing the boardinfo with a pointer.

Fix both issues.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_atmio.c

@@ -350,7 +350,7 @@ static int ni_isapnp_find_board(struct pnp_dev **dev)
 	struct pnp_dev *isapnp_dev = NULL;
 	int i;
 
-	for (i = 0; i < n_ni_boards; i++) {
+	for (i = 0; i < ARRAY_SIZE(ni_boards); i++) {
 		isapnp_dev = pnp_find_dev(NULL,
 					  ISAPNP_VENDOR('N', 'I', 'C'),
 					  ISAPNP_FUNCTION(ni_boards[i].
@@ -377,7 +377,7 @@ static int ni_isapnp_find_board(struct pnp_dev **dev)
 		}
 		break;
 	}
-	if (i == n_ni_boards)
+	if (i == ARRAY_SIZE(ni_boards))
 		return -ENODEV;
 	*dev = isapnp_dev;
 	return 0;
@@ -388,7 +388,7 @@ static int ni_getboardtype(struct comedi_device *dev)
 	int device_id = ni_read_eeprom(dev, 511);
 	int i;
 
-	for (i = 0; i < n_ni_boards; i++) {
+	for (i = 0; i < ARRAY_SIZE(ni_boards); i++) {
 		if (ni_boards[i].device_id == device_id)
 			return i;
 
@@ -406,6 +406,7 @@ static int ni_getboardtype(struct comedi_device *dev)
 static int ni_atmio_attach(struct comedi_device *dev,
 			   struct comedi_devconfig *it)
 {
+	const struct ni_board_struct *boardtype;
 	struct ni_private *devpriv;
 	struct pnp_dev *isapnp_dev;
 	int ret;
@@ -466,9 +467,10 @@ static int ni_atmio_attach(struct comedi_device *dev,
 		return -EIO;
 
 	dev->board_ptr = ni_boards + board;
+	boardtype = comedi_board(dev)
 
-	printk(" %s", boardtype.name);
-	dev->board_name = boardtype.name;
+	printk(" %s", boardtype->name);
+	dev->board_name = boardtype->name;
 
 	/* irq stuff */