[POWERPC] powermac: Constify & voidify get_property()

Now that get_property() returns a void *, there's no need to cast its
return value. Also, treat the return value as const, so we can
constify get_property later.

powermac platform & macintosh driver changes.

Built for pmac32_defconfig, g5_defconfig

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/macintosh/macio_sysfs.c b/drivers/macintosh/macio_sysfs.c
index cae24a1..8566bdf 100644
--- a/drivers/macintosh/macio_sysfs.c
+++ b/drivers/macintosh/macio_sysfs.c
@@ -16,12 +16,12 @@
 compatible_show (struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct of_device *of;
-	char *compat;
+	const char *compat;
 	int cplen;
 	int length = 0;
 
 	of = &to_macio_device (dev)->ofdev;
-	compat = (char *) get_property(of->node, "compatible", &cplen);
+	compat = get_property(of->node, "compatible", &cplen);
 	if (!compat) {
 		*buf = '\0';
 		return 0;
@@ -42,12 +42,12 @@
 			      char *buf)
 {
 	struct of_device *of;
-	char *compat;
+	const char *compat;
 	int cplen;
 	int length;
 
 	of = &to_macio_device (dev)->ofdev;
-	compat = (char *) get_property (of->node, "compatible", &cplen);
+	compat = get_property(of->node, "compatible", &cplen);
 	if (!compat) compat = "", cplen = 1;
 	length = sprintf (buf, "of:N%sT%s", of->node->name, of->node->type);
 	buf += length;