`FOLLY_MAYBE_UNUSED` does not work on Windows
`FOLLY_MAYBE_UNUSED` does not work on Windows

Summary:
`frame` may be unused depending on whether it is compiled with or without asserts.

`FOLLY_MAYBE_UNUSED` is supposed to take care of this, but it does not work on Windows and trips up the comiler:

```
warning C4100: frame: unreferenced formal parameter
```

Reviewed By: johnkearney, akrieger

Differential Revision: D24451220

fbshipit-source-id: 8225640a5e8fd0ceed4ffcc53cea7422a5581d6f

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly