OSV-2021-1510 Heap-buffer-overflow in WriteRingBuffer

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40449 Crash type: Heap-buffer-overflow WRITE Crash state: WriteRingBuffer BrotliDecoderDecompressStream jxl::JxlBoxContentDecoder::Process...