xdp: remove bpf_warn_invalid_xdp_redirect

Given there is a tracepoint that can track the error code
of xdp_do_redirect calls, the WARN_ONCE in bpf_warn_invalid_xdp_redirect
doesn't seem relevant any longer.  Simply remove the function.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/filter.c

@@ -2476,7 +2476,6 @@ static int __bpf_tx_xdp(struct net_device *dev,
 	int err;
 
 	if (!dev->netdev_ops->ndo_xdp_xmit) {
-		bpf_warn_invalid_xdp_redirect(dev->ifindex);
 		return -EOPNOTSUPP;
 	}
 
@@ -2543,7 +2542,6 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
 	fwd = dev_get_by_index_rcu(dev_net(dev), index);
 	ri->ifindex = 0;
 	if (unlikely(!fwd)) {
-		bpf_warn_invalid_xdp_redirect(index);
 		err = -EINVAL;
 		goto out;
 	}
@@ -2564,7 +2562,6 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb)
 	dev = dev_get_by_index_rcu(dev_net(dev), index);
 	ri->ifindex = 0;
 	if (unlikely(!dev)) {
-		bpf_warn_invalid_xdp_redirect(index);
 		return -EINVAL;
 	}
 
@@ -3565,11 +3562,6 @@ void bpf_warn_invalid_xdp_action(u32 act)
 }
 EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
 
-void bpf_warn_invalid_xdp_redirect(u32 ifindex)
-{
-	WARN_ONCE(1, "Illegal XDP redirect to unsupported device ifindex(%i)\n", ifindex);
-}
-
 static bool __is_valid_sock_ops_access(int off, int size)
 {
 	if (off < 0 || off >= sizeof(struct bpf_sock_ops))