Fix a compile error when SDL_JOYSTICK_DISABLED is set

src/events/SDL_events.c

@@ -92,11 +92,13 @@ SDL_Unlock_EventThread(void)
 static __inline__ SDL_bool
 SDL_ShouldPollJoystick()
 {
+#if !SDL_JOYSTICK_DISABLED
     if (SDL_numjoysticks &&
         (!SDL_disabled_events[SDL_JOYAXISMOTION >> 8] ||
          SDL_JoystickEventState(SDL_QUERY))) {
         return SDL_TRUE;
     }
+#endif
     return SDL_FALSE;
 }