[media] v4l2-mem2mem: fix context removal from job queue in v4l2_m2m_streamoff

Just clearing the m2m_ctx->queue list_head will leave the m2m_dev->job_queue
in a broken state and can cause scheduling of device_runs after streamoff was
called.

Signed-off-by: Philipp Zabel <[e-mail]>
Signed-off-by: Kamil Debski <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/v4l2-core/v4l2-mem2mem.c

···
 	m2m_dev = m2m_ctx->m2m_dev;
 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 	/* We should not be scheduled anymore, since we're dropping a queue. */
-	INIT_LIST_HEAD(&m2m_ctx->queue);
+	if (m2m_ctx->job_flags & TRANS_QUEUED)
+		list_del(&m2m_ctx->queue);
 	m2m_ctx->job_flags = 0;
 
 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);