Use stats demux only if selected

modules/misc/stats/demux.c

@@ -63,6 +63,12 @@ int OpenDemux ( vlc_object_t *p_this )
     demux_t *p_demux = (demux_t*)p_this;
     demux_sys_t *p_sys;
 
+    p_demux->p_sys = NULL;
+
+    /* Only when selected */
+    if( *p_demux->psz_demux == '\0' )
+        return VLC_EGENERIC;
+
     msg_Dbg( p_demux, "Init Stat demux" );
 
     p_demux->pf_demux   = Demux;