Wal-Mart has officially closed its online movie download service, less than a year after it launched. A Wal-Mart spokeswoman said the company closed the stone only after Hewlett-Packard, which provided the back end software for the site, “made a business decision to discontinue its video download-only merchant store service.” Wal-Mart did not say whether it had any plans to launch another service using different software. Apple may face…