Minor change to fix compile warning.

On Sun, Aug 10, 2008 at 03:18:35PM -0700, Phil Oester wrote:
> Back in 7/2006, we fixed an issue with the pkttype match mismatching
> on locally generated packets.[1]  At the time, I didn't test the fix
> in the OUTPUT chain, but only in the INPUT chain, where packets showed
> up as PACKET_LOOPBACK.  Unfortunately, when packets are output, they
> aren't tagged as PACKET_LOOPBACK so the fix was incomplete.
> 
> Below is another attempt at fixing the problem in all cases, and fixes
> the original netfilter bugzilla #484 as well as a new bug submission (which
> I can't get the number of since bugzilla is presently down).  
> 
> The fix is somewhat complicated because when broadcast packets hit the
> OUTPUT chain they have no destination MAC attached, so the "simple"
> test for 'all FF' doesn't work for us, and instead we have to consult the
> routing table.
> 
> One other note: since IPv6 doesn't have the concept of "broadcast", perhaps
> the userspace extension shouldn't allow broadcast rules to be added for
> that family?
> 
> Phil
> 
> Signed-off-by: Phil Oester <kernel@linuxace.com>
> 
> [1] http://marc.info/?l=netfilter-devel&m=115318495708540&w=2