cmake: Fix building with -DSDL_HAPTIC=Off

src/haptic/windows/SDL_windowshaptic_c.h

@@ -50,6 +50,7 @@ struct haptic_hwdata
 /*
  * Haptic system effect data.
  */
+#if SDL_HAPTIC_DINPUT || SDL_HAPTIC_XINPUT
 struct haptic_hweffect
 {
 #if SDL_HAPTIC_DINPUT
@@ -60,6 +61,7 @@ struct haptic_hweffect
     XINPUT_VIBRATION vibration;
 #endif
 };
+#endif
 
 /*
 * List of available haptic devices.