REF_PRINT: cast pointer to void to avoid warnings

REF_PRINT: cast pointer to void to avoid warnings

Currently, when configuring OpenSSL and specifying the --strict-warnings
option there are failures like the following one:

crypto/bio/bio_lib.c: In function 'BIO_up_ref':
include/internal/refcount.h:169:25: error: format '%p' expects argument
of type 'void *', but argument 3 has type 'BIO *'
{aka 'struct bio_st *'} [-Werror=format=]
  169 |         fprintf(stderr, "%p:%4d:%s\n", b, b->references, a)
      |                         ^~~~~~~~~~~~~
crypto/bio/bio_lib.c:185:5:
note: in expansion of macro'REF_PRINT_COUNT'
  185 |     REF_PRINT_COUNT("BIO", a);
      |     ^~~~~~~~~~~~~~~
include/internal/refcount.h:169:27: note: format string is defined here
  169 |         fprintf(stderr, "%p:%4d:%s\n", b, b->references, a)
      |                          ~^
      |                           |
      |                           void *
cc1: all warnings being treated as errors

This commit adds casts to avoid the warnings.

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/13389)