KEYS: Don't return EAGAIN to keyctl_assume_authority()

Don't return EAGAIN to keyctl_assume_authority() to indicate that a key could
not be found (ENOKEY is only returned if a negative key is found).  Instead
return ENOKEY in both cases.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/keys/request_key_auth.c

@@ -251,6 +251,8 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id)
 
 	if (IS_ERR(authkey_ref)) {
 		authkey = ERR_CAST(authkey_ref);
+		if (authkey == ERR_PTR(-EAGAIN))
+			authkey = ERR_PTR(-ENOKEY);
 		goto error;
 	}