wifi: rtw89: fix leak in rtw89_core_send_nullfunc()

JIRA: https://issues.redhat.com/browse/RHEL-114889

commit a9f0064
Author: Fedor Pchelkin <pchelkin@ispras.ru>
Date:   Sat Sep 20 00:08:49 2025 +0300

    wifi: rtw89: fix leak in rtw89_core_send_nullfunc()
    
    If there is no rtwsta_link found in rtw89_core_send_nullfunc(), allocated
    skb is leaked.  Free it on the error handling path.
    
    Found by Linux Verification Center (linuxtesting.org).
    
    Fixes: a8ba4ac ("wifi: rtw89: send nullfunc based on the given link")
    Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
    Acked-by: Ping-Ke Shih <pkshih@realtek.com>
    Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
    Link: https://patch.msgid.link/20250919210852.823912-4-pchelkin@ispras.ru

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Author: jtornosm

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

@@ -3441,6 +3441,7 @@ int rtw89_core_send_nullfunc(struct rtw89_dev *rtwdev, struct rtw89_vif_link *rt
 	rtwsta_link = rtwsta->links[rtwvif_link->link_id];
 	if (unlikely(!rtwsta_link)) {
 		ret = -ENOLINK;
+		dev_kfree_skb_any(skb);
 		goto out;
 	}