RSoxBuffers aren't predictable in their content

[tism]

Currently the buffer that's created in rsox_rubyblock_flow with Data_Wrap_Struct doesn't return consistent values. If I load a new input, setup the chain and capture the buffer, the values a different for multiple runs. Is the intention that the passed buffer is only to be inspected at the time the block is called? The previous version that created an array for each buffer works as expected and produces consistent samples.