Patrick McHardy says:

  Never mind, I got it, we never fall through to the second switch
  statement anymore. I think we could simply break when load_pointer
  returns NULL. The switch statement will fall through to the default
  case and return 0 for all cases but 0 > k >= SKF_AD_OFF.

Here's a patch to do just that.

I left BPF_MSH alone because it's really a hack to calculate the IP
header length, which makes no sense when applied to the special data.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>