avformat/4xm: Consider max_streams on reallocating tracks array

Fixes: OOM
Fixes: 41595/clusterfuzz-testcase-minimized-ffmpeg_dem_FOURXM_fuzzer-6355979363549184

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg


Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 0dcd95ef)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/4xm.c

@@ -136,7 +136,8 @@ static int parse_strk(AVFormatContext *s,
         return AVERROR_INVALIDDATA;
 
     track = AV_RL32(buf + 8);
-    if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1) {
+    if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1 ||
+        track >= s->max_streams) {
         av_log(s, AV_LOG_ERROR, "current_track too large\n");
         return AVERROR_INVALIDDATA;
     }