Sometimes during suspend resume, the mdp task thread fails to dequeue buffer and errors out and exits. Later when kthread_stop is called on mdp task, the device crashes in kthread_stop because the mdp task thread is invalid. Change-Id: I42aee61b82c97c378c8497ea70eb53b3eeb24191 CRs-fixed: 394139 Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org> Signed-off-by: Arun Menon <menon@codeaurora.org> Signed-off-by: Neha Pandey <nehap@codeaurora.org>