Fix relative path handling for custom rustfmt

`current_dir` and relative paths to executables works differently on
unix and windows (unix behavior does not make sense), see:

https://github.com/oconnor663/duct.rs/blob/17e30e83a16b202551df4d70d0b2cc174cb53e5d/src/lib.rs#L295-L324

The original motivation to set cwd was to make rustfmt read the
correct rustfmt.toml, but that was future proofing, rather than a bug
fix.

So, let's just remove this and see if breaks or fixes more use-cases.

If support for per-file config is needed, we could use `--config-path`
flag.

0 files changed, 0 insertions, 0 deletions