Fixed detecting the Valve Streaming Gamepad

Fixed the GUID, and compare the contents of the GUID, not just the pointers

platform/windows/joypad_windows.cpp

@@ -97,11 +97,13 @@ bool JoypadWindows::have_device(const GUID &p_guid) {
 
 // adapted from SDL2, works a lot better than the MSDN version
 bool JoypadWindows::is_xinput_device(const GUID *p_guid) {
-	static GUID IID_ValveStreamingGamepad = { MAKELONG(0x28DE, 0x11FF), 0x0000, 0x0000, { 0x00, 0x00, 0x50, 0x49, 0x44, 0x56, 0x49, 0x44 } };
+	static GUID IID_ValveStreamingGamepad = { MAKELONG(0x28DE, 0x11FF), 0x28DE, 0x0000, { 0x00, 0x00, 0x50, 0x49, 0x44, 0x56, 0x49, 0x44 } };
 	static GUID IID_X360WiredGamepad = { MAKELONG(0x045E, 0x02A1), 0x0000, 0x0000, { 0x00, 0x00, 0x50, 0x49, 0x44, 0x56, 0x49, 0x44 } };
 	static GUID IID_X360WirelessGamepad = { MAKELONG(0x045E, 0x028E), 0x0000, 0x0000, { 0x00, 0x00, 0x50, 0x49, 0x44, 0x56, 0x49, 0x44 } };
 
-	if (p_guid == &IID_ValveStreamingGamepad || p_guid == &IID_X360WiredGamepad || p_guid == &IID_X360WirelessGamepad)
+	if (memcmp(p_guid, &IID_ValveStreamingGamepad, sizeof(*p_guid)) == 0 ||
+			memcmp(p_guid, &IID_X360WiredGamepad, sizeof(*p_guid)) == 0 ||
+			memcmp(p_guid, &IID_X360WirelessGamepad, sizeof(*p_guid)) == 0)
 		return true;
 
 	PRAWINPUTDEVICELIST dev_list = nullptr;