tomoyo: Fix typo in comments.

Spotted by developers and codespell program.

Co-developed-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Co-developed-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>