Fix rsa -check option

original problem: if a private key is invaild, nothing outputted.

the error filter in apps/rsa.c is not working any more.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4043)