usb: move children to struct usb_port

The usb_device structure contains an array of usb_device "children".
This array is only valid if the usb_device is a hub, so it makes no
sense to store it there.  Instead, store the usb_device child
in its parent usb_port structure.

Since usb_port is an internal USB core structure, add a new function to
get the USB device child, usb_hub_find_child().  Add a new macro,
usb_hub_get_each_child(), to iterate over all the children attached to a
particular USB hub.

Remove the printing the USB children array pointer from the usb-ip
driver, since it's really not necessary.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/r8a66597-hcd.c b/drivers/usb/host/r8a66597-hcd.c
index 4c634eb..fcc09e5 100644
--- a/drivers/usb/host/r8a66597-hcd.c
+++ b/drivers/usb/host/r8a66597-hcd.c
@@ -2029,15 +2029,14 @@
 static void collect_usb_address_map(struct usb_device *udev, unsigned long *map)
 {
 	int chix;
+	struct usb_device *childdev;
 
 	if (udev->state == USB_STATE_CONFIGURED &&
 	    udev->parent && udev->parent->devnum > 1 &&
 	    udev->parent->descriptor.bDeviceClass == USB_CLASS_HUB)
 		map[udev->devnum/32] |= (1 << (udev->devnum % 32));
 
-	for (chix = 0; chix < udev->maxchild; chix++) {
-		struct usb_device *childdev = udev->children[chix];
-
+	usb_hub_for_each_child(udev, chix, childdev) {
 		if (childdev)
 			collect_usb_address_map(childdev, map);
 	}