Clippy suggests macro expanded code

[Playground link](https://play.rust-lang.org/?version=stable&mode=debug&edition=2015&gist=9c3c44d00c020674ce1c578fcddce690):

```rust
#[macro_use]
extern crate log;

fn main() {
    let r: Result<(), ()> = Ok(());
    match r {
        Err(_) => error!(""),
        _ => {}
    }
}
```



clippy 0.0.212 (9d337313 2018-10-11)
