wifi: rtw89: free unused skb to prevent memory leak

This avoid potential memory leak under power saving mode.
Signed-off-by: Po-Hao Huang <phhuang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220916033811.13862-6-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/core.c

@@ -847,6 +847,7 @@ int rtw89_h2c_tx(struct rtw89_dev *rtwdev,
 		rtw89_debug(rtwdev, RTW89_DBG_FW,
 			    "ignore h2c due to power is off with firmware state=%d\n",
 			    test_bit(RTW89_FLAG_FW_RDY, rtwdev->flags));
+		dev_kfree_skb(skb);
 		return 0;
 	}