crypto_kpp_maxsize() asks for the output buffer size without
caring for errors. It allways assume that will be called after
a valid setkey. Comply with it and return what he wants.
Signed-off-by: NTudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>