[NETLINK]: Use tgid instead of pid for nlmsg_pid

Signed-off-by: Herbert Xu <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/netlink/af_netlink.c

···
 	struct hlist_head *head;
 	struct sock *osk;
 	struct hlist_node *node;
-	s32 pid = current->pid;
+	s32 pid = current->tgid;
 	int err;
 	static s32 rover = -4097;