Re: [PATCH 0/4] MR5436: win32u: Replace sprintf with snprintf to avoid deprecation warnings on macOS.

[Rémi Bernon (＠rbernon)]

```suggestion:-0+0
        len = strlen( buf );
```

Fwiw IMO the strcat would be worth replacing with `snprintf` too, and the buffer size here feels a bit short, i don't see an easy way to make it 100% safe but maybe making it larger would be better.