TEST: Fix link recursion test

Fix the link recursion test to create the ninth keyring in the session keyring
and then link it into the eighth so that we can set the permissions mask upon
it (if we create it *in* the eighth keyring then we can't set the permissions
mask as we don't have possessee permission due to recursion limits preventing
possessee discovery).

Signed-off-by: David Howells <dhowells@redhat.com>