nl80211: Cancel rfkill timeout on deinit

Got segfault, when freeing drv and there exists registered timeout for
blocked rfkill. This patch adds cancel timeout to avoid this.

Signed-off-by: Eduardo Abinader <eduardo.abinader@openbossa.org>

src/drivers/driver_nl80211.c

@@ -4824,6 +4824,7 @@ static void wpa_driver_nl80211_deinit(struct i802_bss *bss)
 
 	netlink_send_oper_ifla(drv->global->netlink, drv->ifindex, 0,
 			       IF_OPER_UP);
+	eloop_cancel_timeout(wpa_driver_nl80211_send_rfkill, drv, drv->ctx);
 	rfkill_deinit(drv->rfkill);
 
 	eloop_cancel_timeout(wpa_driver_nl80211_scan_timeout, drv, drv->ctx);