format code fail, if there is an async function

I wrote this:
```
fn                  test() {
    let a=1;
}
```
after formatted, I got this:
```
fn test() {
    let a = 1;
}
```
that is ok.

but when I wrote this:
```
async fn                  test() {
    let a=1;
}

fn test2           (){}
```

after formatted, nothing happen.

version: rust-analyzer v0.3.1301