changes platform to redhat instead of rhel

I've been having trouble getting this to work on rhel systems and didn't understand why. With platform_family, the output is rhel, but this uses platform, for which the correct value is redhat.

[root@drupal heat_chef]# ohai | grep platform
  "platform": "redhat",
  "platform_version": "6.6",
  "platform_family": "rhel",