net/xfrm_user: Use in_compat_syscall to deny compat syscalls

The code wants to prevent compat code from receiving messages.  Use
in_compat_syscall for this.

Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Steffen Klassert <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: "David S. Miller" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: amluto

net/xfrm/xfrm_user.c

@@ -2449,7 +2449,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	int type, err;
 
 #ifdef CONFIG_COMPAT
-	if (is_compat_task())
+	if (in_compat_syscall())
 		return -ENOTSUPP;
 #endif