Fix print_fp()

Fix print_fp()

The callback-based printing needs to die. But first BIO_set() will die.
We have a FILE *. We have fprintf(). No need to use a static BIO to dump
error codes to said stream.

This basically undoes an unrelated change of "Move crpytlib.h prior bio.h"
from 19 years ago (OpenSSL 25a66ee3). Except we don't cast and check len.

ok jsing (who had a nearly identical diff)