fixed compiler warning by removing an unused variable.

Author: WiSo

lib/libass/libass/ass_render.c

@@ -547,7 +547,6 @@ static void blend_vector_clip(ASS_Renderer *render_priv,
     ASS_Drawing *drawing = render_priv->state.clip_drawing;
     BitmapHashKey key;
     BitmapHashValue *val;
-    int error;
 
     if (!drawing)
         return;
@@ -588,7 +587,7 @@ static void blend_vector_clip(ASS_Renderer *render_priv,
                 render_priv->ftlibrary, outline, 0);
         if (clip_bm == NULL) {
             ass_msg(render_priv->library, MSGL_WARN,
-                "Clip vector rasterization failed: %d. Skipping.", error);
+                "Clip vector rasterization failed. Skipping.");
         }
 
         // Add to cache