[openssl/web] bb73d2: Don't use $? when only the first prerequisite is t...

[Richard Levitte]

  Branch: refs/heads/master
  Home:   https://github.openssl.org/openssl/web
  Commit: bb73d2d424b52605cbd514c87f3a1a69f2aefa84
      https://github.openssl.org/openssl/web/commit/bb73d2d424b52605cbd514c87f3a1a69f2aefa84
  Author: Richard Levitte <levitte at openssl.org>
  Date:   2022-05-09 (Mon, 09 May 2022)

  Changed paths:
    M Makefile

  Log Message:
  -----------
  Don't use $? when only the first prerequisite is to be used

There are a few rules where we were using $?.  This was safe as long
as there was only one prerequisite, even though unnecessary.  However,
when there are multiple prerequisites (such as the recently added
Makefile prerequisites), we lose control on what's actually used in
the commands of the rule.

We take back control by replacing $? with $<, which is always the
first prerequisite.

Reviewed-by: Mark J. Cox <mark at awe.com>
Reviewed-by: Matt Caswell <matt at openssl.org>
(Merged from https://github.com/openssl/web/pull/332)