Inaccurate comment of flush

[metab0t]

The comment says that flush returns the number of bytes written to output buffer, but it returns the encoder. Is the comment outdated?

https://github.com/JuliaStrings/StringEncodings.jl/blob/5ad92b78bfcee0bf488eee85dcac59ab24cbe76b/src/StringEncodings.jl#L219-L234

[nalimilan]

Good catch. I've pushed a commit to remove that comment.

It would also make sense to return nothing rather than the stream, for consistency with what happens with IOStream in Base (though it's not documented). But changing this could break code that relies on it, so we'd better not do it until we tag a breaking release.