ogg: remove useless ret test

Use GST_ELEMENT_REGISTER_DEFINE_CUSTOM instead
of GST_ELEMENT_REGISTER_DEFINE_WITH_CODE if a specific
init needs to be tested before registering the element.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1060>

ext/ogg/gstoggdemux.c

@@ -2298,7 +2298,7 @@ static gboolean gst_ogg_demux_plugin_init (GstPlugin * plugin);
 G_DEFINE_TYPE (GstOggDemux, gst_ogg_demux, GST_TYPE_ELEMENT);
 
 #define _do_init \
-    ret |= gst_ogg_demux_plugin_init (plugin);
+    gst_ogg_demux_plugin_init (plugin);
 GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (oggdemux, "oggdemux", GST_RANK_PRIMARY,
     GST_TYPE_OGG_DEMUX, _do_init);