MXS-2231: Move TLS handshake code into MariaDBClient

The code is now in the correct place and TLS connections with all
authenticators should now work.

server/modules/authenticator/PAM/PAMAuth/pam_client_session.cc

@@ -288,9 +288,9 @@ Buffer PamClientSession::create_auth_change_packet() const
 
 int PamClientSession::authenticate(DCB* dcb)
 {
-    int rval = ssl_authenticate_check_status(dcb);
+    int rval = MXS_AUTH_SSL_COMPLETE;
     MYSQL_session *ses = static_cast<MYSQL_session*>(dcb->data);
-    if (rval == MXS_AUTH_SSL_COMPLETE && *ses->user)
+    if (*ses->user)
     {
         rval = MXS_AUTH_FAILED;
         if (m_state == PAM_AUTH_INIT)