[openssl/openssl] 284888: Document SSL_R_UNEXPECTED_EOF_WHILE_READING

[Matt Caswell]

  Branch: refs/heads/openssl-3.2
  Home:   https://github.com/openssl/openssl
  Commit: 284888cf2eddd6f52e6cea8aea8127e3c74e2a84
      https://github.com/openssl/openssl/commit/284888cf2eddd6f52e6cea8aea8127e3c74e2a84
  Author: Matt Caswell <matt at openssl.org>
  Date:   2024-01-18 (Thu, 18 Jan 2024)

  Changed paths:
    M doc/man3/SSL_get_error.pod
    M ssl/record/rec_layer_s3.c

  Log Message:
  -----------
  Document SSL_R_UNEXPECTED_EOF_WHILE_READING

Also document that it is ok to use this for control flow decisions.

Reviewed-by: Tom Cosgrove <tom.cosgrove at arm.com>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23304)

(cherry picked from commit ead44e19fa3ff7d189876081880f1adb3dfdf30b)