staging: wilc1000: don't use wdev while setting tx power

WILC doesn't support per-vif tx power, and hence, wdev will always be
null in calls to set_tx_power.
Instead, wiphy should be used to execute the operation
Signed-off-by: Adham Abozaeid <adham.abozaeid@microchip.com>
Link: https://lore.kernel.org/r/20191004214011.7623-1-adham.abozaeid@microchip.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/wilc_wfi_cfgoperations.c

@@ -1685,9 +1685,22 @@ static int set_tx_power(struct wiphy *wiphy, struct wireless_dev *wdev,
 			enum nl80211_tx_power_setting type, int mbm)
 {
 	int ret;
+	int srcu_idx;
 	s32 tx_power = MBM_TO_DBM(mbm);
-	struct wilc_vif *vif = netdev_priv(wdev->netdev);
+	struct wilc *wl = wiphy_priv(wiphy);
+	struct wilc_vif *vif;
 
+	if (!wl->initialized)
+		return -EIO;
+
+	srcu_idx = srcu_read_lock(&wl->srcu);
+	vif = wilc_get_wl_to_vif(wl);
+	if (IS_ERR(vif)) {
+		srcu_read_unlock(&wl->srcu, srcu_idx);
+		return -EINVAL;
+	}
+
+	netdev_info(vif->ndev, "Setting tx power %d\n", tx_power);
 	if (tx_power < 0)
 		tx_power = 0;
 	else if (tx_power > 18)
@@ -1695,6 +1708,7 @@ static int set_tx_power(struct wiphy *wiphy, struct wireless_dev *wdev,
 	ret = wilc_set_tx_power(vif, tx_power);
 	if (ret)
 		netdev_err(vif->ndev, "Failed to set tx power\n");
+	srcu_read_unlock(&wl->srcu, srcu_idx);
 
 	return ret;
 }