Wrong suggestion in identical conversion lint

[sigmaSd]

Hi,
clippy 0.0.212 (265318d 2019-05-17)

code:

fn main() {}

fn _z(a: &std::path::Path) -> std::io::Result<()> {
    for _ in std::fs::read_dir(a)? {}
    Ok(())
}

clippy:

warning: identical conversion
 --> src/main.rs:4:14
  |
4 |     for _ in std::fs::read_dir(a)? {}
  |              ^^^^^^^^^^^^^^^^^^^^^ help: consider removing `std::fs::read_dir(a)?()`: `std::fs::read_dir(a)?`
  |
  = note: #[warn(clippy::identity_conversion)] on by default
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#identity_conversion

removing ? and using unwrap for example make the lint warning disappear as it should

[sigmaSd]

duplicate #4133