wl_client_add_resource has been deprecated in the Wayland API in
favour of wl_client_add_object which returns a pointer to a
wl_resource which it allocates instead of the compositor having to
embed it in a larger struct. As far as I understand the idea is to
eventually make wl_resource completely opaque. This patch changes
Cogland accordingly.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit adb971954757dffb9ddecf8c9091b96756424800)