We send direct probe to broadcast address, as some APs do not respond to
unicast PROBE frames when unassociated. Broadcast frames are not acked,
so we can not use that for trigger MLME state machine, but we need to
use old timeout mechanism.

This fixes authentication timed out like below:

[ 1024.671974] wlan6: authenticate with 54:e6:fc:98:63:fe
[ 1024.694125] wlan6: direct probe to 54:e6:fc:98:63:fe (try 1/3)
[ 1024.695450] wlan6: direct probe to 54:e6:fc:98:63:fe (try 2/3)
[ 1024.700586] wlan6: send auth to 54:e6:fc:98:63:fe (try 3/3)
[ 1024.701441] wlan6: authentication with 54:e6:fc:98:63:fe timed out

With fix, we have:

[ 4524.198978] wlan6: authenticate with 54:e6:fc:98:63:fe
[ 4524.220692] wlan6: direct probe to 54:e6:fc:98:63:fe (try 1/3)
[ 4524.421784] wlan6: send auth to 54:e6:fc:98:63:fe (try 2/3)
[ 4524.423272] wlan6: authenticated
[ 4524.423811] wlan6: associate with 54:e6:fc:98:63:fe (try 1/3)
[ 4524.427492] wlan6: RX AssocResp from 54:e6:fc:98:63:fe (capab=0x431 status=0 aid=1)

Cc: stable@vger.kernel.org # 3.9
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>