Use the precalculated size instead of obfuscating the message length
calculation by first subtracting the netlink header length from size
and then use the NLMSG_LENGTH() macro to add it back again.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>