glib-aux: drop unused _nm_dbus_connection_call_finish()

This wasn't used. It also doesn't make much sense, because
g_dbus_connection_call() accepts a reply type argument. So if you want
to check the reply type, you can do so when making the call.

That differs from g_dbus_proxy_call(), where this might make some sense
and is actually used.

While at it, also drop _nm_dbus_typecheck_response() from the header
file. It seems not general purpose enough and is not necessarily a great
pattern. Because,

- for g_dbus_connection_call() you either specify the reply_type when making
  the call, or you do some more elaborate handling of the result -- not merely
  _nm_dbus_typecheck_response().

- for g_dbus_proxy_call(), you can use _nm_dbus_proxy_call_finish() to
  get it, or again, you want some non-trivial type checking.

src/libnm-glib-aux/nm-dbus-aux.c

@@ -526,39 +526,6 @@ nm_dbus_connection_call_blocking(NMDBusConnectionCallBlockingData *data, GError
 
 /*****************************************************************************/
 
-/**
- * _nm_dbus_typecheck_response:
- * @response: the #GVariant response to check.
- * @reply_type: the expected reply type. It may be %NULL to perform no
- *   checking.
- * @error: (allow-none): the error in case the @reply_type does not match.
- *
- * Returns: %TRUE, if @response is of the expected @reply_type.
- */
-gboolean
-_nm_dbus_typecheck_response(GVariant *response, const GVariantType *reply_type, GError **error)
-{
-    g_return_val_if_fail(response, FALSE);
-
-    if (!reply_type)
-        return TRUE;
-    if (g_variant_is_of_type(response, reply_type))
-        return TRUE;
-
-    /* This is the same error code that g_dbus_connection_call() returns if
-     * @reply_type doesn't match.
-     */
-    g_set_error(error,
-                G_IO_ERROR,
-                G_IO_ERROR_INVALID_ARGUMENT,
-                _("Method returned type '%s', but expected '%s'"),
-                g_variant_get_type_string(response),
-                g_variant_type_peek_string(reply_type));
-    return FALSE;
-}
-
-/*****************************************************************************/
-
 typedef struct {
     char               *signal_name;
     const GVariantType *signature;
@@ -694,6 +661,28 @@ _nm_dbus_proxy_signal_connect_data(GDBusProxy         *proxy,
 
 /*****************************************************************************/
 
+static gboolean
+_nm_dbus_typecheck_response(GVariant *response, const GVariantType *reply_type, GError **error)
+{
+    g_return_val_if_fail(response, FALSE);
+
+    if (!reply_type)
+        return TRUE;
+    if (g_variant_is_of_type(response, reply_type))
+        return TRUE;
+
+    /* This is the same error code that g_dbus_connection_call() returns if
+     * @reply_type doesn't match.
+     */
+    g_set_error(error,
+                G_IO_ERROR,
+                G_IO_ERROR_INVALID_ARGUMENT,
+                _("Method returned type '%s', but expected '%s'"),
+                g_variant_get_type_string(response),
+                g_variant_type_peek_string(reply_type));
+    return FALSE;
+}
+
 /**
  * _nm_dbus_proxy_call_finish:
  * @proxy: A #GDBusProxy.
@@ -723,17 +712,3 @@ _nm_dbus_proxy_call_finish(GDBusProxy         *proxy,
         nm_clear_pointer(&variant, g_variant_unref);
     return variant;
 }
-
-GVariant *
-_nm_dbus_connection_call_finish(GDBusConnection    *dbus_connection,
-                                GAsyncResult       *result,
-                                const GVariantType *reply_type,
-                                GError            **error)
-{
-    GVariant *variant;
-
-    variant = g_dbus_connection_call_finish(dbus_connection, result, error);
-    if (variant && !_nm_dbus_typecheck_response(variant, reply_type, error))
-        nm_clear_pointer(&variant, g_variant_unref);
-    return variant;
-}

src/libnm-glib-aux/nm-dbus-aux.h

@@ -276,9 +276,6 @@ nm_g_variant_tuple_get_u(GVariant *v, guint32 *out_u)
 
 /*****************************************************************************/
 
-gboolean
-_nm_dbus_typecheck_response(GVariant *response, const GVariantType *reply_type, GError **error);
-
 gulong _nm_dbus_proxy_signal_connect_data(GDBusProxy         *proxy,
                                           const char         *signal_name,
                                           const GVariantType *signature,
@@ -313,9 +310,4 @@ GVariant *_nm_dbus_proxy_call_finish(GDBusProxy         *proxy,
                                      const GVariantType *reply_type,
                                      GError            **error);
 
-GVariant *_nm_dbus_connection_call_finish(GDBusConnection    *dbus_connection,
-                                          GAsyncResult       *result,
-                                          const GVariantType *reply_type,
-                                          GError            **error);
-
 #endif /* __NM_DBUS_AUX_H__ */