TOMOYO: Allow wildcard for execute permission.

Some applications create and execute programs dynamically. We need to accept
wildcard for execute permission because such programs contain random suffix
in their filenames. This patch loosens up regulation of string parameters.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>