Vim indentation broken with multiline function calls in struct definitions.

Consider the following code:

``` rust
fn main() {
    let x = X {
        a: 1,
        b: fffff(1,
                 2),
        c: 1,
    };
    let _ = x;
}
```

Opening a new line while on the `c`-line puts the cursor here:

``` rust
    let x = X {
        a: 1,
        b: fffff(1,
                 2),
        c: 1,
                 X
    };
```

cc @chris-morgan
