[INET]: Prevent out-of-sync truesize on ip_fragment slow path
When ip_fragment has to hit the slow path the value of skb->truesize
may go out of sync because we would have updated it without changing
the packet length. This violates the constraints on truesize.
This patch postpones the update of skb->truesize to prevent this.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>