Cleaning up apu/ and renaming -private files to _flags.

Part of #296.

src/xenia/hid/xinput/xinput_hid.cc

@@ -15,25 +15,7 @@ namespace xe {
 namespace hid {
 namespace xinput {
 
-void InitializeIfNeeded();
-void CleanupOnShutdown();
-
-void InitializeIfNeeded() {
-  static bool has_initialized = false;
-  if (has_initialized) {
-    return;
-  }
-  has_initialized = true;
-
-  //
-
-  atexit(CleanupOnShutdown);
-}
-
-void CleanupOnShutdown() {}
-
 std::unique_ptr<InputDriver> Create(InputSystem* input_system) {
-  InitializeIfNeeded();
   return std::make_unique<XInputInputDriver>(input_system);
 }