AppArmor: fix mapping of META_READ to audit and quiet flags

The mapping of AA_MAY_META_READ for the allow mask was also being mapped
to the audit and quiet masks. This would result in some operations being
audited when the should not.

This flaw was hidden by the previous audit bug which would drop some
messages that where supposed to be audited.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>