Removed the vi format comments from the source

Vim users can use the [editorconfig plugin](https://github.com/editorconfig/editorconfig-vim) to automatically set tab spacing for the SDL coding style.

Fixes https://github.com/libsdl-org/SDL/issues/6903

src/thread/ngage/SDL_syssem.cpp

@@ -159,5 +159,3 @@ int SDL_SemPost(SDL_sem *sem)
     sema.Signal();
     return 0;
 }
-
-/* vi: set ts=4 sw=4 expandtab: */