MPTCP: fix lock class name family in pm_nl_create_listen_socket

[ Upstream commit 7ab4a7c5d969642782b8a5b608da0dd02aa9f229 ]

In mptcp_pm_nl_create_listen_socket(), use entry->addr.family
instead of sk->sk_family for lock class setup. The 'sk' parameter
is a netlink socket, not the MPTCP subflow socket being created.

Fixes: cee4034 ("mptcp: fix lockdep false positive in mptcp_pm_nl_create_listen_socket()")
Signed-off-by: Li Xiasong <lixiasong1@huawei.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260319112159.3118874-1-lixiasong1@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Li Xiasong

net/mptcp/pm_kernel.c

@@ -824,7 +824,7 @@ static struct lock_class_key mptcp_keys[2];
 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 					    struct mptcp_pm_addr_entry *entry)
 {
-	bool is_ipv6 = sk->sk_family == AF_INET6;
+	bool is_ipv6 = entry->addr.family == AF_INET6;
 	int addrlen = sizeof(struct sockaddr_in);
 	struct sockaddr_storage addr;
 	struct sock *newsk, *ssk;