selinux: Minor cleanups

commit 420591128cb206201dc444c2d42fb6f299b2ecd0 upstream.

Fix the comment for function __inode_security_revalidate, which returns
an integer.

Use the LABEL_* constants consistently for isec->initialized.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Alexander Grund <theflamefire89@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>