Update cfn-init-data path to match current Heat

Since April 2013 /var/lib/cloud/data has been deprecated.
Os-collect-config does not search that path, so this means
seed-stack-config is completely broken now that os-collect-config is
used instead of cfn-hup.

Change-Id: Ifb040f3d5e6d8326e13c1a25adb39dc7e5dc1a6c
Merge "Update cfn-init-data path to match current Heat"