af_asyncts: Use llabs instead of labs for 64-bit variable

libavfilter/af_asyncts.c:212:9: warning: absolute value function 'labs' given an argument of type 'int64_t' (aka 'long long') but has parameter of type 'long' which may cause truncation of value [-Wabsolute-value]

libavfilter/af_asyncts.c

@@ -209,7 +209,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
     delta    = pts - s->pts - get_delay(s);
     out_size = avresample_available(s->avr);
 
-    if (labs(delta) > s->min_delta ||
+    if (llabs(delta) > s->min_delta ||
         (s->first_frame && delta && s->first_pts != AV_NOPTS_VALUE)) {
         av_log(ctx, AV_LOG_VERBOSE, "Discontinuity - %"PRId64" samples.\n", delta);
         out_size = av_clipl_int32((int64_t)out_size + delta);