media: raspberrypi: cfe: Fix min_reqbufs_allocation

The driver checks if "vq->max_num_buffers + *nbuffers < 3", but
vq->max_num_buffers is (by default) 32, so the check is never true. Nor
does the check make sense.

The original code in the BSP kernel was "vq->num_buffers + *nbuffers <
3", but got mangled along the way to upstream. The intention was to make
sure that at least 3 buffers are allocated.

Fix this by removing the bad lines and setting q->min_reqbufs_allocation
to three.

Signed-off-by: Tomi Valkeinen <[e-mail]>
Reviewed-by: Hans Verkuil <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/platform/raspberrypi/rp1-cfe/cfe.c

···
 	cfe_dbg(cfe, "%s: [%s] type:%u\n", __func__, node_desc[node->id].name,
 		node->buffer_queue.type);
 
-	if (vq->max_num_buffers + *nbuffers < 3)
-		*nbuffers = 3 - vq->max_num_buffers;
-
 	if (*nplanes) {
 		if (sizes[0] < size) {
 			cfe_err(cfe, "sizes[0] %i < size %u\n", sizes[0], size);
···
 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
 	q->lock = &node->lock;
 	q->min_queued_buffers = 1;
+	q->min_reqbufs_allocation = 3;
 	q->dev = &cfe->pdev->dev;
 
 	ret = vb2_queue_init(q);