apparmor: fix resource audit messages when auditing peer

Resource auditing is using the peer field which is not available
when the rlim data struct is used, because it is a different element
of the same union. Accessing peer during resource auditing could
cause garbage log entries or even oops the kernel.

Move the rlim data block into the same struct as the peer field
so they can be used together.

CC: <stable@vger.kernel.org>
Fixes: 86b92cb7 ("apparmor: move resource checks to using labels")
Signed-off-by: John Johansen <john.johansen@canonical.com>