iwlwifi: fix activating inactive stations

When authentication/association timed out, the driver would
complain bitterly, printing the message
ACTIVATE a non DRIVER active station id ... addr ...

The cause turns out to be that when the AP station is added
but we don't associate, the IWL_STA_UCODE_INPROGRESS is set
but never cleared. This then causes iwl_restore_stations()
to attempt to resend it because it uses the flag internally
and uploads even if it didn't set it itself.

To fix this issue and not upload the station again when it
has already been removed by mac80211, clear the flag after
adding it in case we add it only for association.

Cc: stable@vger.kernel.org
Reviewed-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>