uhci: fix uhci_async_cancel_all

We update the QTAILQ in the loop, thus we must use the SAFE version
to make sure we don't touch the queue struct after freeing it.

https://bugzilla.novell.com/show_bug.cgi?id=766310Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 77fa9aee)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

hw/usb/hcd-uhci.c

@@ -288,10 +288,10 @@ static void uhci_async_cancel_device(UHCIState *s, USBDevice *dev)
 
 static void uhci_async_cancel_all(UHCIState *s)
 {
-    UHCIQueue *queue;
+    UHCIQueue *queue, *nq;
     UHCIAsync *curr, *n;
 
-    QTAILQ_FOREACH(queue, &s->queues, next) {
+    QTAILQ_FOREACH_SAFE(queue, &s->queues, next, nq) {
         QTAILQ_FOREACH_SAFE(curr, &queue->asyncs, next, n) {
             uhci_async_unlink(curr);
             uhci_async_cancel(curr);