[POWERPC] pci_controller->arch_data really is a struct device_node *

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
index b483903..85d4d89 100644
--- a/arch/powerpc/kernel/pci_dn.c
+++ b/arch/powerpc/kernel/pci_dn.c
@@ -133,7 +133,7 @@
  */
 void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
 {
-	struct device_node * dn = (struct device_node *) phb->arch_data;
+	struct device_node *dn = phb->dn;
 	struct pci_dn *pdn;
 
 	/* PHB nodes themselves must not match */