apparmor: Fix regression in stacking due to label flags

The unconfined label flag is not being computed correctly. It
should only be set if all the profiles in the vector are set, which
is different than what is required for the debug and stale flag
that are set if any on the profile flags are set.

Fixes: c1ed5da1 ("apparmor: allow label to carry debug flags")
Signed-off-by: John Johansen <john.johansen@canonical.com>