unused macro MPN_PTR_SWAP in mini-gmp.c

[Paul Eggert]

On 3/17/22 11:32, Marco Bodrato wrote:
>   mpz_swap (mpz_t u, mpz_t v)
>   {
>     MP_SIZE_T_SWAP (u->_mp_size, v->_mp_size);
> -  MP_SIZE_T_SWAP (u->_mp_alloc, v->_mp_alloc);
> -  MP_PTR_SWAP (u->_mp_d, v->_mp_d);
> +  MPN_PTR_SWAP (u->_mp_d, u->_mp_alloc, v->_mp_d, v->_mp_alloc);

Thank you, this looks good.