xinput1_3: Added stub code for XInputGetKeystroke.

dlls/xinput1_3/xinput1_3.spec

 @ stdcall XInputEnable(long)
 @ stdcall XInputSetState(long ptr)
 @ stdcall XInputGetState(long ptr)
-@ stub XInputGetKeystroke #(long long ptr)
+@ stdcall XInputGetKeystroke(long long ptr)
 @ stdcall XInputGetCapabilities(long long ptr)
 @ stub XInputGetDSoundAudioDeviceGuids #(long ptr ptr)
 @ stub XInputGetBatteryInformation

dlls/xinput1_3/xinput1_3_main.c

@@ -79,6 +79,18 @@ DWORD WINAPI XInputGetState(DWORD dwUserIndex, XINPUT_STATE* pState)
     return ERROR_BAD_ARGUMENTS;
 }
 
+DWORD WINAPI XInputGetKeystroke(DWORD dwUserIndex, DWORD dwReserve, PXINPUT_KEYSTROKE pKeystroke)
+{
+    FIXME("(%d %d %p) Stub!\n", dwUserIndex, dwReserve, pKeystroke);
+
+    if (dwUserIndex < XUSER_MAX_COUNT)
+    {
+        return ERROR_DEVICE_NOT_CONNECTED;
+        /* If controller exists then return ERROR_SUCCESS */
+    }
+    return ERROR_BAD_ARGUMENTS;
+}
+
 DWORD WINAPI XInputGetCapabilities(DWORD dwUserIndex, DWORD dwFlags, XINPUT_CAPABILITIES* pCapabilities)
 {
     FIXME("(%d %d %p)\n", dwUserIndex, dwFlags, pCapabilities);