[openssl/openssl] 18af4d: Make parsing of piped data in `speed.c` more robust

[faramir-dev]

  Branch: refs/heads/master
  Home:   https://github.com/openssl/openssl
  Commit: 18af4d154cc563a5b02409215a576276caece0f4
      https://github.com/openssl/openssl/commit/18af4d154cc563a5b02409215a576276caece0f4
  Author: Daniel Fiala <daniel at openssl.org>
  Date:   2022-11-24 (Thu, 24 Nov 2022)

  Changed paths:
    M apps/speed.c

  Log Message:
  -----------
  Make parsing of piped data in `speed.c` more robust

Fixes openssl#19050

Reviewed-by: Paul Dale <pauli at openssl.org>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19238)