[clang-tidy] Fix type names in modernize-use-unique/shared_ptr checks.

Summary:
If the class being created in unique_ptr is in anonymous nampespace, the
anonymous namespace will be included in the apply-fixes. This patch fix
this.

```
namespace {
class Foo {};
}
std::unique_ptr<Foo> f;
f.reset(new Foo());
// Before the change: f = std::make_unique<(annonymous namespace)::Foo>();
// After the change: f = std::make_unique<Foo>();
```

Reviewers: alexfh

Reviewed By: alexfh

Subscribers: JDevlieghere, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D34286

llvm-svn: 306378