If a scan is queued in STA mode while the interface is in state direct
probe, authenticate or associate the scan is delayed until the interface
enters disabled or associated state. But in case of direct probe-,
authentication- or association- timeout sta_work will not be scheduled
anymore (without external trigger) and thus the pending scan is not
executed and prevents a new scan from being triggered (-EBUSY).

Fix this by queueing the sta work again after direct probe-, authentication-
and association- timeout.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>