crypto: cryptd - pass through absence of ->setkey()

When the cryptd template is used to wrap an unkeyed hash algorithm,
don't install a ->setkey() method to the cryptd instance.  This change
is necessary for cryptd to keep working with unkeyed hash algorithms
once we start enforcing that ->setkey() is called when present.

Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 552e3a8..457ae3e 100644
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -914,7 +914,8 @@
 	inst->alg.finup  = cryptd_hash_finup_enqueue;
 	inst->alg.export = cryptd_hash_export;
 	inst->alg.import = cryptd_hash_import;
-	inst->alg.setkey = cryptd_hash_setkey;
+	if (crypto_shash_alg_has_setkey(salg))
+		inst->alg.setkey = cryptd_hash_setkey;
 	inst->alg.digest = cryptd_hash_digest_enqueue;
 
 	err = ahash_register_instance(tmpl, inst);