mt76: add mac80211 driver for MT7915 PCIe-based chipsets

Hello Ryder Lee,

The patch e57b7901469f: "mt76: add mac80211 driver for MT7915 PCIe-based chipsets" from Apr 25, 2020, leads to the following static checker warning:

	drivers/net/wireless/mediatek/mt76/mt7915/mcu.c:1576 mt7915_mcu_add_smps()
	error: 'wtbl_hdr' dereferencing possible ERR_PTR()

drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
1558 int mt7915_mcu_add_smps(struct mt7915_dev *dev, struct ieee80211_vif *vif,
1559 struct ieee80211_sta *sta)
1560 {

  1561          struct mt7915_vif *mvif = (struct mt7915_vif *)vif->drv_priv;
  1562          struct mt7915_sta *msta = (struct mt7915_sta *)sta->drv_priv;
  1563          struct wtbl_req_hdr *wtbl_hdr;
  1564          struct tlv *sta_wtbl;
  1565          struct sk_buff *skb;
  1566  
  1567          skb = mt7915_mcu_alloc_sta_req(dev, mvif, msta,
  1568                                         MT7915_STA_UPDATE_MAX_SIZE);
  1569          if (IS_ERR(skb))
  1570                  return PTR_ERR(skb);
  1571  
  1572          sta_wtbl = mt7915_mcu_add_tlv(skb, STA_REC_WTBL, sizeof(struct tlv));
  1573  
  1574          wtbl_hdr = mt7915_mcu_alloc_wtbl_req(dev, msta, WTBL_SET, sta_wtbl,
                ^^^^^^^^

No error handling.

1575 &skb);
1576 mt7915_mcu_wtbl_smps_tlv(skb, sta, sta_wtbl, wtbl_hdr);
1577
1578 return __mt76_mcu_skb_send_msg(&dev->mt76, skb,
1579 MCU_EXT_CMD_STA_REC_UPDATE, true);
1580 }

regards,
dan carpenter