memory leaks in wtvfile_open_sector()

[Suhwan]

Summary of the bug:
There're memory leaks detected in wtvfile_open_sector()
How to reproduce:

% ffmpeg_g -i $PoC tmp.lxf

ffmpeg version N-95464-g7056ddc0e0 Copyright (c) 2000-2019 the FFmpeg developers
built with clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
configuration: --cc=clang --cxx=clang++ --ld=clang --enable-debug

Here's Valgrind log

==10445== HEAP SUMMARY:
==10445==     in use at exit: 5,236 bytes in 38 blocks
==10445==   total heap usage: 102 allocs, 64 frees, 79,475 bytes allocated
==10445== 
==10445== 4,412 (264 direct, 4,148 indirect) bytes in 1 blocks are definitely lost in loss record 33 of 33
==10445==    at 0x9FE3E76: memalign (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==10445==    by 0x9FE3F91: posix_memalign (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==10445==    by 0x592EC7D: av_malloc (mem.c:87)
==10445==    by 0x14731F6: avio_alloc_context (aviobuf.c:140)
==10445==    by 0x1AB7BA6: wtvfile_open_sector (wtvdec.c:238)
==10445==    by 0x1AB7BA6: wtvfile_open2 (wtvdec.c:289)
==10445==    by 0x1AB3355: read_header (wtvdec.c:989)
==10445==    by 0x1A145FC: avformat_open_input (utils.c:633)
==10445==    by 0x42FFF7: open_input_file (ffmpeg_opt.c:1105)
==10445==    by 0x42DE5E: open_files (ffmpeg_opt.c:3283)
==10445==    by 0x42DB4F: ffmpeg_parse_options (ffmpeg_opt.c:3323)
==10445==    by 0x487BB3: main (ffmpeg.c:4862)
==10445== 
==10445== LEAK SUMMARY:
==10445==    definitely lost: 264 bytes in 1 blocks
==10445==    indirectly lost: 4,148 bytes in 3 blocks
==10445==      possibly lost: 0 bytes in 0 blocks
==10445==    still reachable: 824 bytes in 34 blocks
==10445==         suppressed: 0 bytes in 0 blocks
==10445== Reachable blocks (those to which a pointer was found) are not shown.
==10445== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==10445== 
==10445== For counts of detected and suppressed errors, rerun with: -v
==10445== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

Please confirm.
Thanks

[Suhwan]

poc

[mkver]

Fixed in 373c1c9b691fd4c6831b3a114a006b639304c2af.