avformat/mov: zero initialize the index ranges buffer

Signed-off-by: James Almer <jamrial@gmail.com>

libavformat/mov.c

@@ -3860,7 +3860,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
     }
 
     // allocate the index ranges array
-    msc->index_ranges = av_malloc((msc->elst_count + 1) * sizeof(msc->index_ranges[0]));
+    msc->index_ranges = av_calloc((msc->elst_count + 1), sizeof(msc->index_ranges[0]));
     if (!msc->index_ranges) {
         av_log(mov->fc, AV_LOG_ERROR, "Cannot allocate index ranges buffer\n");
         return;