Decompression finalize fails after frame error

[morris25]

If a LZ4Decompressor cannot decode the frame header, finalize() gives a malloc error.

julia> using CodecLz4

julia> codec = LZ4Decompressor()
CodecLz4.LZ4Decompressor(Base.RefValue{Ptr{CodecLz4.LZ4F_dctx}}(Ptr{CodecLz4.LZ4F_dctx} @0x0000000000000000))

julia> try
           data = transcode(codec, "not properly formatted")
           println(data)
           
       catch e
           println(e)
       finally
           try
               CodecLz4.check_context_initialized(codec.dctx[])
               println("codec exists")
           catch
               println("empty codec")
           end
           CodecLz4.TranscodingStreams.finalize(codec)
       end
ErrorException("LZ4F_decompress: ERROR_frameType_unknown")
codec exists
julia(25795,0x7fffa6174340) malloc: *** error for object 0x309371a21220309: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug

signal (6): Abort trap: 6

Looking into the LZ4 source code here, it seems that the temporary buffers don't get allocated properly before they are freed.