Treat the keyboard and pads differently.

We basically never want two pads active at once, but keyboard is
different.  So, they need to be treated differently.

Fixes #1212.

Windows/XinputDevice.cpp

@@ -55,9 +55,7 @@ int XinputDevice::UpdateState(InputState &input_state) {
 
 		// If there's an XInput pad, skip following pads. This prevents DInput and XInput
 		// from colliding.
-		if (left.x != 0.0f || left.y != 0.0f)
-			return UPDATESTATE_SKIP_NEXT;
-		return 0;
+		return UPDATESTATE_SKIP_PAD;
 	} else {
 		// wait check_delay frames before polling the controller again
 		this->gamepad_idx = -1;