The `serializer()`, `deserializer_{fd,no_fd,simple}()` functions
take a string argument named "namespace", but they do not use it.
So remove the argument.
Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>