LSM: drop duplicated words in header file comments

Drop the doubled words "the" and "and" in comments.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Cc: linux-security-module@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>