crypto: crypto4xx - Use crypto_ahash_set_reqsize

This patch makes crypto4xx use crypto_ahash_set_reqsize to avoid
accessing crypto_ahash directly.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/amcc/crypto4xx_core.c b/drivers/crypto/amcc/crypto4xx_core.c
index 4c0dfb2..cb7be42 100644
--- a/drivers/crypto/amcc/crypto4xx_core.c
+++ b/drivers/crypto/amcc/crypto4xx_core.c
@@ -1001,7 +1001,8 @@
 	if (alg->cra_type == &crypto_ablkcipher_type)
 		tfm->crt_ablkcipher.reqsize = sizeof(struct crypto4xx_ctx);
 	else if (alg->cra_type == &crypto_ahash_type)
-		tfm->crt_ahash.reqsize = sizeof(struct crypto4xx_ctx);
+		crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
+					 sizeof(struct crypto4xx_ctx));
 
 	return 0;
 }