OSV-2023-840 Null-dereference READ in isvcd_parse_inter_slice_data_cavlc_enh_lyr

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=62290 Crash type: Null-dereference READ Crash state: isvcdparseinterslicedatacavlcenhlyr isvcdparseepslice isvcdparsedecodesliceextnal...