kernel-interface: Remove reqid parameter from get_spi/get_cpi() methods

The reqid is not strictly required, as we set the reqid with the update
call when installing the negotiated SA.

If we don't need a reqid at this stage, we can later allocate the reqid in
the kernel backend once the SA parameters have been fully negotaited. This
allows us to assign the same reqid for the same selectors to avoid conflicts
on backends this is necessary.

src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c

@@ -236,14 +236,14 @@ METHOD(kernel_ipsec_t, get_features, kernel_feature_t,
 
 METHOD(kernel_ipsec_t, get_spi, status_t,
 	private_kernel_libipsec_ipsec_t *this, host_t *src, host_t *dst,
-	u_int8_t protocol, u_int32_t reqid, u_int32_t *spi)
+	u_int8_t protocol, u_int32_t *spi)
 {
 	return ipsec->sas->get_spi(ipsec->sas, src, dst, protocol, spi);
 }
 
 METHOD(kernel_ipsec_t, get_cpi, status_t,
 	private_kernel_libipsec_ipsec_t *this, host_t *src, host_t *dst,
-	u_int32_t reqid, u_int16_t *cpi)
+	u_int16_t *cpi)
 {
 	return NOT_SUPPORTED;
 }