TOMOYO: Reduce lines by using common path for addition and deletion.

Since the codes for adding an entry and removing an entry are similar, we can
save some lines by using "if (is_delete) { ... } else { ... }" branches.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>