Samsung said Wednesday it is buying Canadian cloud-printing firm PrinterOn, as a part of its push to bulk up its lineup of mobile-software products, particularly for corporate clients. Ontario-based PrinterOn, which develops technology that allows users to print materials using their smartphones by connecting to printers through the Web, will operate as a wholly owned unit of Samsung Electronics in Canada. Financial terms weren’t disclosed. The acquisition is the latest in a string of recent purchases by the South Korean company to broaden its mobile-software offerings as it faces slowing growth and rising competition from phone makers in China and emerging markets.