crypto: algif_skcipher - Add nokey compatibility path

commit a0fa2d03 upstream.

This patch adds a compatibility path to support old applications
that do acept(2) before setkey.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>