TOMOYO: Fix domain transition failure warning.

Commit bd03a3e4

 "TOMOYO: Add policy namespace support." introduced policy
namespace. But as of /sbin/modprobe is executed from initramfs/initrd, profiles
for target domain's namespace is not defined because /sbin/tomoyo-init is not
yet called.

Reported-by: Jamie Nguyen <jamie@tomoyolinux.co.uk>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>