fix distro name
fix distro name

Summary: Missed this when switching from spaces to underscores in distro names

Reviewed By: krallin

Differential Revision: D32693527

fbshipit-source-id: 658504d76c96defd3f1a217ada8b05f99c841ede

facebook/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman