apparmor: fix module parameter handling

The 'aabool' wrappers actually pass off to the 'bool' parse functions,
so you should use the same check function.  Similarly for aauint and
uint.

(Note that 'bool' module parameters also allow 'int', which is why you
got away with this, but that's changing very soon.)

Cc: linux-security-module@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>