tomoyo: use hwight16() in tomoyo_domain_quota_is_ok()

hwight16() is much faster. While we are at it, no need to include
"perm =" part into data_race() macro, for perm is a local variable
that cannot be accessed by other threads.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>