kernel_setsockopt removed in cb8e59cc

[   13s] /home/abuild/rpmbuild/BUILD/drbd-9.0.24~1+git.17730ea3/default/drbd_transport_tcp.c: In function 'dtt_nodelay':
[   13s] /home/abuild/rpmbuild/BUILD/drbd-9.0.24~1+git.17730ea3/default/drbd_transport_tcp.c:158:9: error: implicit declaration of funct
ion 'kernel_setsockopt'; did you mean 'kernel_getsockname'? [-Werror=implicit-function-declaration]
[   13s]   158 |  (void) kernel_setsockopt(socket, SOL_TCP, TCP_NODELAY, (char *)&val, sizeof(val));
[   13s]       |         ^~~~~~~~~~~~~~~~~                                                                                              [   13s]       |         kernel_getsockname
[   14s] cc1: some warnings being treated as errors

In 518846b54, some kernel_setsockopt() are removed, but not all...

diff -Naur drbd-9.0.26~0+git.9114a038.orig/drbd/drbd_transport_tcp.c drbd-9.0.26~0+git.9114a038/drbd/drbd_transport_tcp.c
--- drbd-9.0.26~0+git.9114a038.orig/drbd/drbd_transport_tcp.c	2020-12-09 14:06:22.117468473 +0800
+++ drbd-9.0.26~0+git.9114a038/drbd/drbd_transport_tcp.c	2020-12-09 14:06:54.989546999 +0800
@@ -883,7 +883,6 @@
 	struct socket *dsocket, *csocket;
 	struct net_conf *nc;
 	int timeout, err;
-	int one = 1;
 	bool ok;
 
 	dsocket = NULL;
@@ -1065,9 +1064,14 @@
 	dsocket->sk->sk_sndtimeo = timeout;
 	csocket->sk->sk_sndtimeo = timeout;
 
+#ifndef COMPAT_HAVE_TCP_SOCK_SET_CORK
+	int one = 1;
 	err = kernel_setsockopt(dsocket, SOL_SOCKET, SO_KEEPALIVE, (char *)&one, sizeof(one));
 	if (err)
 		tr_warn(transport, "Failed to enable SO_KEEPALIVE %d\n", err);
+#else
+	sock_set_keepalive(dsocket->sk);
+#endif
 
 	return 0;