UB in macro

https://github.com/pozm/bsod-rs/blob/9a80e6c801e9b7ada458c0acd0240010d89fa5bc/src/lib.rs#L27

this code is UB, as pointed by `CStr::as_ptr` documentation (https://doc.rust-lang.org/std/ffi/struct.CString.html#method.as_ptr):

```rust
// Do not do this:
let ptr = CString::new("Hello").expect("CString::new failed").as_ptr();
unsafe {
    // `ptr` is dangling
    *ptr;
}
```