ieee1394: ohci1394: call PMac code in shutdown only for proper machines

There has been an if(...) missing, for ages.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/ieee1394/ohci1394.c b/drivers/ieee1394/ohci1394.c
index 3c9dc7d..628130a 100644
--- a/drivers/ieee1394/ohci1394.c
+++ b/drivers/ieee1394/ohci1394.c
@@ -3517,7 +3517,7 @@
 #ifdef CONFIG_PPC_PMAC
 	/* On UniNorth, power down the cable and turn off the chip clock
 	 * to save power on laptops */
-	{
+	if (machine_is(powermac)) {
 		struct device_node* ofn = pci_device_to_OF_node(ohci->dev);
 
 		if (ofn) {