config: check return vlaue after set

src/config.c

@@ -385,8 +385,16 @@ int cntlr_config_add_agent_radio(struct controller_config *c, char *al_mac,
 		goto out_pkg;
 
 	ret = set_value(ctx, pkg, section, "agent_id", al_mac, UCI_TYPE_STRING);
+	if (ret)
+		goto out_pkg;
+
 	ret = set_value(ctx, pkg, section, "macaddr", radio_mac, UCI_TYPE_STRING);
+	if (ret)
+		goto out_pkg;
+
 	ret = set_value(ctx, pkg, section, "band", band, UCI_TYPE_STRING);
+	if (ret)
+		goto out_pkg;
 
 	uci_commit(ctx, &pkg, false);