media: videobuf2: quick fix for dmabuf type

It's a bug in 4.4 kernel

Change-Id: I38807830d1a4289af65ebaed9c9ab179d2328827
Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>

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

@@ -105,6 +105,9 @@ static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		length = (b->memory == VB2_MEMORY_USERPTR)
 			? b->length : vb->planes[0].length;
 
+		if (b->memory == VB2_MEMORY_DMABUF)
+			return 0;
+
 		if (b->bytesused > length)
 			return -EINVAL;
 	}