usb-mtp: use safe variant when cleaning events list

usb_mtp_inotify_cleanup uses QLIST_FOREACH to pick events
from a list and free them which is incorrect. Use QLIST_FOREACH_SAFE
instead.
Signed-off-by: NBandan Das <bsd@redhat.com>
Message-id: 1450861787-16213-2-git-send-email-bsd@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/usb/dev-mtp.c

@@ -556,7 +556,7 @@ static int usb_mtp_inotify_init(MTPState *s)
 
 static void usb_mtp_inotify_cleanup(MTPState *s)
 {
-    MTPMonEntry *e;
+    MTPMonEntry *e, *p;
 
     if (!s->inotifyfd) {
         return;
@@ -565,7 +565,7 @@ static void usb_mtp_inotify_cleanup(MTPState *s)
     qemu_set_fd_handler(s->inotifyfd, NULL, NULL, s);
     close(s->inotifyfd);
 
-    QTAILQ_FOREACH(e, &s->events, next) {
+    QTAILQ_FOREACH_SAFE(e, &s->events, next, p) {
         QTAILQ_REMOVE(&s->events, e, next);
         g_free(e);
     }