chardev/socket: Use qcrypto_tls_creds_check_endpoint()

Avoid accessing QCryptoTLSCreds internals by using
the qcrypto_tls_creds_check_endpoint() helper.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

chardev/char-socket.c

@@ -1402,18 +1402,12 @@ static void qmp_chardev_open_socket(Chardev *chr,
             return;
         }
         object_ref(OBJECT(s->tls_creds));
-        if (is_listen) {
-            if (s->tls_creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
-                error_setg(errp, "%s",
-                           "Expected TLS credentials for server endpoint");
-                return;
-            }
-        } else {
-            if (s->tls_creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
-                error_setg(errp, "%s",
-                           "Expected TLS credentials for client endpoint");
-                return;
-            }
+        if (!qcrypto_tls_creds_check_endpoint(s->tls_creds,
+                                          is_listen
+                                          ? QCRYPTO_TLS_CREDS_ENDPOINT_SERVER
+                                          : QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
+                                          errp)) {
+            return;
         }
     }
     s->tls_authz = g_strdup(sock->tls_authz);