backports: handle no_fcs change in struct sk_buff

backports: handle no_fcs change in struct sk_buff

In kernel 3.4 a new field no_fcs was introduced to struct sk_buff.
Address this by putting ifdef around the code.

commit 3bdc0eba0b8b47797f4a76e377dd8360f317450f
Author: Ben Greear <greearb@candelatech.com>
Date:   Sat Feb 11 15:39:30 2012 +0000

    net: Add framework to allow sending packets with customized CRC.

git describe --contains 3bdc0eba0b8b47797f4a76e377dd8360f317450f
v3.4-rc1~177^2~207

Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>