Comments after the first one in empty struct are not formatted nicely

struct Struct {
    // Hello, this is my
    // struct where I haven't added
    // any fields yet.
    // TODO: add fields
}

If you format this code, it becomes:

struct Struct {
    // Hello, this is my
// struct where I haven't added
// any fields yet.
// TODO: add fields
}

I expected it to stay the way it is because it already looks perfectly fine and leaving only the first comment indented looks odd.

[calebcartwright]

Thanks for sharing! Seems to occur with other struct types
e.g.

struct Foo(
    // Bar
    // Baz
    // Qux
);

so probably a general indentation issue with empty struct defs

For anyone interested in working on this a good starting place to look in the code would probably be here:
https://github.com/rust-lang/rustfmt/blob/master/src/items.rs#L1040-L1055