wl12xx: Make sure HW is available in sched scan ops

The sched_scan_(stop|start) ops fails to check for WL1271_STATE_OFF.
This can lead to a race where the driver tries to access the HW
while it's off.

Fix this by checking for WL1271_STATE_OFF before accessing the HW.
Signed-off-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/main.c

@@ -3108,6 +3108,11 @@ static int wl1271_op_sched_scan_start(struct ieee80211_hw *hw,
 
 	mutex_lock(&wl->mutex);
 
+	if (wl->state == WL1271_STATE_OFF) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
 	ret = wl1271_ps_elp_wakeup(wl);
 	if (ret < 0)
 		goto out;
@@ -3139,6 +3144,9 @@ static void wl1271_op_sched_scan_stop(struct ieee80211_hw *hw,
 
 	mutex_lock(&wl->mutex);
 
+	if (wl->state == WL1271_STATE_OFF)
+		goto out;
+
 	ret = wl1271_ps_elp_wakeup(wl);
 	if (ret < 0)
 		goto out;