Poll for the initial controller state when using DirectInput

This fixes getting a deflected axis as the first buffered input reading on a generic USB controller (G-Shark GS-GP702)

src/joystick/windows/SDL_windowsjoystick_c.h

@@ -76,6 +76,7 @@ struct joystick_hwdata
     LPDIRECTINPUTDEVICE8 InputDevice;
     DIDEVCAPS Capabilities;
     SDL_bool buffered;
+    SDL_bool first_update;
     input_t Inputs[MAX_INPUTS];
     int NumInputs;
     int NumSliders;