commit 4613012d upstream.

As suggested by Eric Dumazet this change replaces the
complaints by the compiler when misusing the API.
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>