Don't prompt for session on `haskell-process-do-info` etc.

when run, `haskell-process-do-info`, always prompts me to `choose Haskell session: [my-haskell-session]`, with the correct default, and I have to hit enter. This stops me from binding it as a callback to mousedown. I'm new to haskell-mode, but most things work, and in particular a session is active and my project compiles.

the relevant call graph seems to be:

```
(haskell-process-do-info nil)
-> (haskell-process-do-simple-echo ...)
-> (haskell-interactive-process)
-> (haskell-interactive-session)
-> (or (haskell-session-maybe) (... (or (haskell-session-from-buffer) (haskell-session-choose))))
```

the calls between `(haskell-interactive-process)` and `(haskell-session-maybe)`, inclusively, return non-nil when evaluated in any `.hs` file in my project.

can't haskell mode infer the right session from a project (there is one session per project, yes?), as there is one project per module. Or can I assert that I only have one session open in any Emacs thing (I know the architecture can handle multiple)?

Thank you