of: Always use 'struct device.of_node' to get device node pointer.

The following structure elements duplicate the information in
'struct device.of_node' and so are being eliminated.  This patch
makes all readers of these elements use device.of_node instead.

(struct of_device *)->node
(struct dev_archdata *)->prom_node (sparc)
(struct dev_archdata *)->of_node (powerpc & microblaze)

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/char/viotape.c b/drivers/char/viotape.c
index 1144a04..42f7fa4 100644
--- a/drivers/char/viotape.c
+++ b/drivers/char/viotape.c
@@ -866,7 +866,7 @@
 {
 	int i = vdev->unit_address;
 	int j;
-	struct device_node *node = vdev->dev.archdata.of_node;
+	struct device_node *node = vdev->dev.of_node;
 
 	if (i >= VIOTAPE_MAX_TAPE)
 		return -ENODEV;