'j' is specified as modifier for "greatest-width integer type", which in
practice means 64 bits on both 32- and 64-bit platforms. Since we rely
on __attribute__((__format__(__printf__,...))) to sanitize BIO_print
format, we can use it to denote [u]int64_t-s in platform-neutral manner.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3083)