The pcap support was not working because of some linking problems (expressing
the construct in Kbuild was a bit difficult) and because there was no user
request.  Now that this has come back, here's the support.

This has been tested and works on both 32 and 64-bit hosts, even when
"cross-"building 32-bit binaries.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>