Test obtain_device_info when board name has no matching device config.

-- File fs/open~_tmp_sysinfo_board_name.txt --
unknown,device
-- End --

-- Testcase --
let ar = require('advanced_reboot');
let api = ar["luci.advanced-reboot"];
let result = api.obtain_device_info.call();
printf("%J\n", result);
-- End --

-- Expect stdout --
{ "error": "NO_BOARD_NAME_MATCH", "rom_board_name": "unknown,device" }
-- End --