[openssl/openssl] 055d02: Fix accumulated index comments in felem_inv for p521

[Rohan McLure]

  Branch: refs/heads/master
  Home:   https://github.com/openssl/openssl
  Commit: 055d029610712a281aed0c23ddd3c8f4dbf40f80
      https://github.com/openssl/openssl/commit/055d029610712a281aed0c23ddd3c8f4dbf40f80
  Author: Rohan McLure <rmclure at linux.ibm.com>
  Date:   2022-11-28 (Mon, 28 Nov 2022)

  Changed paths:
    M crypto/ec/ecp_nistp521.c

  Log Message:
  -----------
  Fix accumulated index comments in felem_inv for p521

Comments in felem_inv refer to the logarithm with respect to in of the
element that has just been computed. The last two such annotations are
incorrect. By Fermat's last theorem, we hope to compute in^(p-2) in
GF(2^521-1), as such we expect the final index we reach to be 2^521-3.

CLA: Trivial

Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
Reviewed-by: Matt Caswell <matt at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19765)