Don't ignore ASN1 when checking for undocumented symbols

Don't ignore ASN1 when checking for undocumented symbols

When we run "make doc-nits" (which happens during travis runs) it will
complain if we add any new symbols that aren't documented. However it
was suppressing anything starting with ASN1. There's no reason why we
should allow ASN1 symbols to go undocumented any more than any others.
Therefore we remove that exception.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10980)