crypto: af_alg - Add nokey compatibility path

[ Upstream commit 37766586c965d63758ad542325a96d5384f4a8c9 ]

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

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>