ssl_session: Define unconditionally the endpoint field

The endpoint field is needed to serialize/deserialize
a session in TLS 1.2 the same way it is needed in the
TLS 1.3 case: client specific fields that should not
be in the serialized version on server side if both
TLS client and server are enabled in the TLS library.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_tls12_client.c b/library/ssl_tls12_client.c
index 0c5af87..5469850 100644
--- a/library/ssl_tls12_client.c
+++ b/library/ssl_tls12_client.c
@@ -1268,6 +1268,7 @@
     ssl->tls_version = (mbedtls_ssl_protocol_version) mbedtls_ssl_read_version(buf,
                                                                                ssl->conf->transport);
     ssl->session_negotiate->tls_version = ssl->tls_version;
+    ssl->session_negotiate->endpoint = ssl->conf->endpoint;
 
     if (ssl->tls_version < ssl->conf->min_tls_version ||
         ssl->tls_version > ssl->conf->max_tls_version) {