Otherwise we might end up creating directories under sstate-cache with whatever
random umask has been selected for the task that we're trying to package. This
would be a bad thing since it might result in losing group write access for
newly created dirs, and/or losing group read access for the sstate files
themselves.
Signed-off-by: Phil Blundell <philb@gnu.org> Signed-off-by: Saul Wold <sgw@linux.intel.com>