Sync some code style improvements from the OpenSSL 1.1.1 branch,

Sync some code style improvements from the OpenSSL 1.1.1 branch,
which is still under a free license.  No functional change.

- No need to #include <openssl/lhash.h> here.
- return is not a function.
- Do not use the pointless macro BIO_s_file_internal().
- No need to check for NULL before X509_CRL_free(3).

This includes parts of the following OpenSSL commits from
the 2015 to 2017 timeframe: 222561fe, 9982cbbb, f32b0abe, 26a7d938

OK tb@