[PATCH] powerpc: minor cleanup of void ptr deref

Minor: use macro to perform void pointer deref; this may someday help
avoid pointer typecasting errors.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/powermac/pci.c b/arch/powerpc/platforms/powermac/pci.c
index 443be52..e0b66f5 100644
--- a/arch/powerpc/platforms/powermac/pci.c
+++ b/arch/powerpc/platforms/powermac/pci.c
@@ -326,7 +326,7 @@
 	else
 		busdn = hose->arch_data;
 	for (dn = busdn->child; dn; dn = dn->sibling)
-		if (dn->data && PCI_DN(dn)->devfn == devfn)
+		if (PCI_DN(dn) && PCI_DN(dn)->devfn == devfn)
 			break;
 	if (dn == NULL)
 		return -1;