rustdoc: Struct variant fields don't have the right path in the search index

``` rust
#![crate_type="lib"]
#![feature(struct_variant)]

pub enum Enum {
    Bar { pub name: String }
}
```

Running rustdoc on this, and then searching for `name` yields one result, with the incorrect path `foo::Enum::Enum::name`. Because the path is wrong, the link is also broken.
