rootplug: Remove redundant initialization.

We don't need to explicitly initialize to cap_* because
it will be filled by security_fixup_ops().

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>