Reset the fd to -1 after PreInit

We open and remove the device immediately, but the fd was left on the old
value. This makes debugging harder, since the fd looks correct when it isn't.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/libinput.c

@@ -580,6 +580,7 @@ static int xf86libinput_pre_init(InputDriverPtr drv,
 	libinput_device_ref(device);
 	libinput_path_remove_device(device);
 
+	pInfo->fd = -1;
 	pInfo->private = driver_data;
 	driver_data->path = path;
 	driver_data->device = device;