[openssl/openssl] bae1d4: Fix documentation for some i2d return values.

[Shane]

  Branch: refs/heads/openssl-3.1
  Home:   https://github.com/openssl/openssl
  Commit: bae1d405cf08854eb354354c7ea7ff8f5a4865eb
      https://github.com/openssl/openssl/commit/bae1d405cf08854eb354354c7ea7ff8f5a4865eb
  Author: slontis <shane.lontis at oracle.com>
  Date:   2022-11-07 (Mon, 07 Nov 2022)

  Changed paths:
    M doc/man3/OSSL_CMP_MSG_get0_header.pod
    M doc/man3/d2i_PrivateKey.pod

  Log Message:
  -----------
  Fix documentation for some i2d return values.

i2d_XXX_bio and i2d_XXX_fp return either 0 or 1.
Other i2d_XXX functions return the number of bytes or negative on error.

Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18427)

(cherry picked from commit 943051d0f9ce8dcb38707774a5757a5dc436704f)