dereference p_libvlc->p_vlm after the media clean up

(cherry picked from commit 88e497880b252bc2a73b8e14cd9b6c5ddc13bc77)
Signed-off-by: Sébastien Escudier <sebastien-devel@celeos.eu>

src/input/vlm.c

@@ -214,16 +214,15 @@ void vlm_Delete( vlm_t *p_vlm )
     vlc_mutex_lock( &vlm_mutex );
     assert( p_vlm->users > 0 );
     if( --p_vlm->users == 0 )
-    {
         assert( libvlc_priv(p_vlm->p_libvlc)->p_vlm == p_vlm );
-        libvlc_priv(p_vlm->p_libvlc)->p_vlm = NULL;
-    }
     else
         p_vlm = NULL;
-    vlc_mutex_unlock( &vlm_mutex );
 
     if( p_vlm == NULL )
+    {
+        vlc_mutex_unlock( &vlm_mutex );
         return;
+    }
 
     /* Destroy and release VLM */
     vlc_mutex_lock( &p_vlm->lock );
@@ -242,6 +241,9 @@ void vlm_Delete( vlm_t *p_vlm )
         vlc_object_release( p_vlm->p_vod );
     }
 
+    libvlc_priv(p_vlm->p_libvlc)->p_vlm = NULL;
+    vlc_mutex_unlock( &vlm_mutex );
+
     vlc_mutex_lock( &p_vlm->lock_manage );
     p_vlm->input_state_changed = true;
     vlc_cond_signal( &p_vlm->wait_manage );