crypto: hash - Fix async import on shash algorithm

The function shash_async_import did not initialise the descriptor
correctly prior to calling the underlying shash import function.

This patch adds the required initialisation.
Reported-by: Miloslav Trmac <mitr@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/shash.c

@@ -310,7 +310,13 @@ static int shash_async_export(struct ahash_request *req, void *out)
 
 static int shash_async_import(struct ahash_request *req, const void *in)
 {
-	return crypto_shash_import(ahash_request_ctx(req), in);
+	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
+	struct shash_desc *desc = ahash_request_ctx(req);
+
+	desc->tfm = *ctx;
+	desc->flags = req->base.flags;
+
+	return crypto_shash_import(desc, in);
 }
 
 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)