cdf: fix memleak in dav1d_cdf_thread_unref
Observed with clusterfuzz-testcase-minimized-dav1d_fuzzer_mt-5700224002031616. Credits to oss-fuzz.
Observed with clusterfuzz-testcase-minimized-dav1d_fuzzer_mt-5700224002031616. Credits to oss-fuzz.
VideoLAN code repository instance