[POWERPC] Make vio_bus_type static

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index ee15c22..1d7b272 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -39,6 +39,8 @@
 
 extern struct kset devices_subsys; /* needed for vio_find_name() */
 
+static struct bus_type vio_bus_type;
+
 static struct vio_dev vio_bus_device  = { /* fake "parent" device */
 	.name = vio_bus_device.dev.bus_id,
 	.type = "",
@@ -388,7 +390,7 @@
 	return 0;
 }
 
-struct bus_type vio_bus_type = {
+static struct bus_type vio_bus_type = {
 	.name = "vio",
 	.dev_attrs = vio_dev_attrs,
 	.uevent = vio_hotplug,