tkm: Use the inbound flag do determine peer role in CHILD_SA exchange

This was not available during initial implementation, but fits just fine to
avoid reconstructing the peer role.

src/charon-tkm/src/tkm/tkm_kernel_ipsec.c

@@ -86,11 +86,10 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
 	u_int32_t tfc, lifetime_cfg_t *lifetime, u_int16_t enc_alg, chunk_t enc_key,
 	u_int16_t int_alg, chunk_t int_key, ipsec_mode_t mode,
 	u_int16_t ipcomp, u_int16_t cpi, u_int32_t replay_window,
-	bool _initiator, bool encap, bool esn, bool inbound,
+	bool initiator, bool encap, bool esn, bool inbound,
 	linked_list_t* src_ts, linked_list_t* dst_ts)
 {
 	esa_info_t esa;
-	bool initiator;
 	esp_spi_type spi_loc, spi_rem;
 	host_t *local, *peer;
 	chunk_t *nonce_loc, *nonce_rem;
@@ -113,9 +112,6 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
 		return SUCCESS;
 	}
 
-	/* Initiator if encr_r is passed as enc_key to the inbound add_sa call */
-	/* TODO: does the new _initiator parameter have the same meaning? */
-	initiator = esa.is_encr_r && inbound;
 	if (initiator)
 	{
 		spi_loc = spi;