fs: dlm: use sk->sk_socket instead of con->sock

stable inclusion
from stable-v5.10.94
commit 98923ebb034b8c405c5e9e216834021fe72d7875
bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=98923ebb034b8c405c5e9e216834021fe72d7875

--------------------------------

[ Upstream commit feb704bd ]

Instead of dereference "con->sock" we can get the socket structure over
"sk->sk_socket" as well. This patch will switch to this behaviour.
Signed-off-by: NAlexander Aring <aahringo@redhat.com>
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

fs/dlm/lowcomms.c

@@ -480,8 +480,7 @@ static void lowcomms_error_report(struct sock *sk)
 		goto out;
 
 	orig_report = listen_sock.sk_error_report;
-	if (con->sock == NULL ||
-	    kernel_getpeername(con->sock, (struct sockaddr *)&saddr) < 0) {
+	if (kernel_getpeername(sk->sk_socket, (struct sockaddr *)&saddr) < 0) {
 		printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
 				   "sending to node %d, port %d, "
 				   "sk_err=%d/%d\n", dlm_our_nodeid(),