input: avoids double mutex locking

src/input/input.c

@@ -2558,8 +2558,6 @@ static void InputUpdateMeta( input_thread_t *p_input, vlc_meta_t *p_meta )
             input_ExtractAttachmentAndCacheArt( p_input );
     }
     free( psz_arturl );
- 
-    input_item_SetPreparsed( p_item, VLC_TRUE );
 
     /* A bit ugly */
     p_meta = NULL;
@@ -2570,6 +2568,8 @@ static void InputUpdateMeta( input_thread_t *p_input, vlc_meta_t *p_meta )
     }
     vlc_mutex_unlock( &p_item->lock );
 
+    input_item_SetPreparsed( p_item, VLC_TRUE );
+
     if( i_arturl_event == VLC_TRUE )
     {
         vlc_event_t event;