Any other users of bpf_*_filter that take a struct sock_fprog from
userspace will need to be able to also accept a compat_sock_fprog
if the arch supports compat calls.  This change allows the existing
compat_sock_fprog be shared.
Signed-off-by: NWill Drewry <wad@chromium.org>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NEric Paris <eparis@redhat.com>

v18: tasered by the apostrophe police
v14: rebase/nochanges
v13: rebase on to 88ebdda6
v12: rebase on to linux-next
v11: introduction
Signed-off-by: NJames Morris <james.l.morris@oracle.com>