cb_destroy
void (*cb_destroy)(struct cc_var *ccv);
.cb_destroy = cubic_cb_destroy,
if (tcp->tcp_cc_algo != NULL && tcp->tcp_cc_algo->cb_destroy != NULL)
tcp->tcp_cc_algo->cb_destroy(&tcp->tcp_ccv);
if (tcp->tcp_cc_algo->cb_destroy != NULL)
tcp->tcp_cc_algo->cb_destroy(&tcp->tcp_ccv);
if (CC_ALGO(tcp)->cb_destroy != NULL) {
CC_ALGO(tcp)->cb_destroy(&tcp->tcp_ccv);
cb_destroy(pci_p);
cb_destroy(pci_p);
extern void cb_destroy(pci_t *pci_p);