AES_GMAC_Reinit
void AES_GMAC_Reinit(void *, const uint8_t *, u_int);
AES_GMAC_Reinit(&ctx->gmac, iv, ivlen);
.Reinit = AES_GMAC_Reinit,
.Reinit = AES_GMAC_Reinit,
.Reinit = AES_GMAC_Reinit,