vp3: Assert on invalid filter_limit values.

Signed-off-by: Dale Curtis <dalecurtis@chromium.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/vp3.c

@@ -396,6 +396,7 @@ static void init_loop_filter(Vp3DecodeContext *s)
     int value;
 
     filter_limit = s->filter_limit_values[s->qps[0]];
+    av_assert0(filter_limit < 128U);
 
     /* set up the bounding values */
     memset(s->bounding_values_array, 0, 256 * sizeof(int));