media: atomisp: Use vb2_get_buffer() instead of directly access to buffers array

Use vb2_get_buffer() instead of direct access to the vb2_queue bufs array.
This allows us to change the type of the bufs in the future.
No need to check the result of vb2_get_buffer, vb2_ioctl_dqbuf() already
checked that it is valid.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
CC: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/staging/media/atomisp/pci/atomisp_ioctl.c

@@ -1059,7 +1059,7 @@ static int atomisp_dqbuf_wrapper(struct file *file, void *fh, struct v4l2_buffer
 	if (ret)
 		return ret;
 
-	vb = pipe->vb_queue.bufs[buf->index];
+	vb = vb2_get_buffer(&pipe->vb_queue, buf->index);
 	frame = vb_to_frame(vb);
 
 	buf->reserved = asd->frame_status[buf->index];