Function ieee80211_sta_reset_conn_monitor has been
resetting probe_send_count too early and nullfunc
check was never called after succesfull ack.
Reported-by: Magnus Cederlöf <mcider@gmail.com> Tested-by: Magnus Cederlöf <mcider@gmail.com> Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>