Multiline comment inside struct get unidented 

Take the following code:

```rust
struct MyStruct {
    /* Some comment.
    /// Some field
    some_field: Option<String>,
    */
}
```

Looks reasonable to me, but rustfmt changes it to the following:

```rust
struct MyStruct {
    /* Some comment.
/// Some field
some_field: Option<String>,
*/}
```

Version:
```
rustfmt 1.4.37-stable (a178d032 2021-07-26)
```