[Bug 50553] SetEnvironmentVariableW function sets last error on deleting non-existent variable

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=50553

--- Comment #1 from Mikhail Gorodetsky  ---
Forgot `L` literal before "SomeValue" in

```
result = SetEnvironmentVariableW(L"PERL5LIB", "SomeValue");
```

correct should be

```
result = SetEnvironmentVariableW(L"PERL5LIB", L"SomeValue");
```

Just checked, it didn't change anything.