[media] videobuf2-core: remove duplicated code

Remove duplicated test of buffer presence at streamon
Signed-off-by: NVictor Lambret <victor.lambret.ext@parrot.com>
Acked-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/v4l2-core/videobuf2-core.c

@@ -2151,10 +2151,6 @@ static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
 		return -EINVAL;
 	}
 
-	if (!q->num_buffers) {
-		dprintk(1, "no buffers have been allocated\n");
-		return -EINVAL;
-	}
 	if (q->num_buffers < q->min_buffers_needed) {
 		dprintk(1, "need at least %u allocated buffers\n",
 				q->min_buffers_needed);