For future reference the problem isn't the locale, since the code syntax for HLSL is the same across languages, and arguments in functions are always separated by commas. Instead, the error seems to come from Direct3D 11 expecting a different amount of arguments for a function.
The fix you're showing us should actually cause a syntax error on Windows. Perhaps Unity is compiling it anyway because you're not on Windows using d3d11?
Do you get the same error in Unity 2017?