sock_cmsg_send() can return different error codes and not only -EINVAL, and we should properly propagate them. Fixes: c14ac9451c34 ("sock: enable timestamping using control messages") Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>