nutdec: make chapter start and length uint64_t to prevent overflows.

Patch by Anton Khirnov wyskas chez gmail punto com

Originally committed as revision 22127 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/nutdec.c

@@ -389,8 +389,8 @@ static void set_disposition_bits(AVFormatContext* avf, char* value, int stream_i
 static int decode_info_header(NUTContext *nut){
     AVFormatContext *s= nut->avf;
     ByteIOContext *bc = s->pb;
-    uint64_t tmp;
-    unsigned int stream_id_plus1, chapter_start, chapter_len, count;
+    uint64_t tmp, chapter_start, chapter_len;
+    unsigned int stream_id_plus1, count;
     int chapter_id, i;
     int64_t value, end;
     char name[256], str_value[1024], type_str[256];