[PATCH] softmac: Fixed handling of deassociation from AP

In 2.6.19 a deauthentication from the AP doesn't start a
reassociation by the softmac code. It appears that
mac->associnfo.associating must be set and the
ieee80211softmac_assoc_work function must be scheduled. This patch
fixes that.

Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>