crypto: ccp - Fill the result buffer only on digest, finup, and final ops

Any change to the result buffer should only happen on final, finup
and digest operations. Changes to the buffer for update, import, export,
etc, are not allowed.

Fixes: 66d7b9f6175e ("crypto: testmgr - test misuse of result in ahash")
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>