avformat/movenc: move variable to a more local block

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/movenc.c

@@ -2507,12 +2507,12 @@ static int mov_write_mvex_tag(AVIOContext *pb, MOVMuxContext *mov)
 static int mov_write_mvhd_tag(AVIOContext *pb, MOVMuxContext *mov)
 {
     int max_track_id = 1, i;
-    int64_t max_track_len_temp, max_track_len = 0;
+    int64_t max_track_len = 0;
     int version;
 
     for (i = 0; i < mov->nb_streams; i++) {
         if (mov->tracks[i].entry > 0 && mov->tracks[i].timescale) {
-            max_track_len_temp = av_rescale_rnd(mov->tracks[i].track_duration,
+            int64_t max_track_len_temp = av_rescale_rnd(mov->tracks[i].track_duration,
                                                 MOV_TIMESCALE,
                                                 mov->tracks[i].timescale,
                                                 AV_ROUND_UP);