mac80211: fix FT roaming

During FT roaming, wpa_supplicant attempts to set the
key before association. This used to be rejected, but
as a side effect of my commit 66e67e41


("mac80211: redesign auth/assoc") the key was accepted
causing hardware crypto to not be used for it as the
station isn't added to the driver yet.

It would be possible to accept the key and then add it
to the driver when the station has been added. However,
this may run into issues with drivers using the state-
based station adding if they accept the key only after
association like it used to be.

For now, revert to the behaviour from before the auth
and assoc change.

Cc: stable@vger.kernel.org
Reported-by: Cédric Debarge <cedric.debarge@acksys.fr>
Tested-by: Cédric Debarge <cedric.debarge@acksys.fr>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>