Code review comment for lp:~mir-team/mir/expose-debug-buffer-id-to-client

I agree about separating the debug APIs, but this is an existing issue. Vis:

/**
 * Return the ID of a surface (only useful for debug output).
 * \param [in] surface The surface
 * \return An internal ID that identifies the surface
 */
int mir_surface_get_id(MirSurface *surface);

(I'm sure that used to be called mir_debug_surface_id())