Remove suspicious and suspiciously dead code

A destructor would never have to release its own object, since the
destructor is only called when the object is not referenced anymore.
On the other hand, it is not clear to me whether SD objects still need
a destructor.

src/playlist/services_discovery.c

@@ -33,8 +33,6 @@
 #include "../libvlc.h"
 
 
-static void services_discovery_Destructor ( services_discovery_t * p_sd );
-
 /*
  * Services discovery
  * Basically you just listen to Service discovery event through the
@@ -130,17 +128,6 @@ void vlc_sd_Stop ( services_discovery_t * p_sd )
     p_sd->p_module = NULL;
 }
 
-/***********************************************************************
- * Destructor
- ***********************************************************************/
-static void services_discovery_Destructor ( services_discovery_t * p_sd )
-{
-    assert(!p_sd->p_module); /* Forgot to call Stop */
-
-    vlc_event_manager_fini( &p_sd->event_manager );
-    vlc_object_release( p_sd );
-}
-
 /***********************************************************************
  * GetLocalizedName
  ***********************************************************************/