status: unbreak the (deprecated) --no-lock-index option

When core Git introduced the --no-optional-locks option in v2.15.0, it
knowingly implemented a different solution to the same problem, causing
merge conflicts and requiring an upgrade to Team Explorer.

To lessen the impact of that, I tried to handle --no-lock-index by
triggering the same code as --no-optional-locks, with a big fat warning
that --no-lock-index is deprecated.

In the last-minute rebasing frenzy leading up to Git for Windows
v2.15.0, however, I managed to forget about the validation of that code
(and I also wanted to update the commit message, which I also forgot).

And of course my patch broke the feature, by using the `no_lock_index`
variable before the command-line options were parsed :-(

This commit fixes it (and also reverts another patch that is no longer
necessary, which persisted the --no-lock-index flag to spawned
processes). It is a combination of two separate fixup commits that
already made it into Git for Windows' `master` branch.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

builtin/commit.c

@@ -1428,23 +1428,18 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage_with_options(builtin_status_usage, builtin_status_options);
 
-	if (no_lock_index) {
-		warning("--no-lock-index is deprecated, use --no-optional-locks"
-			" instead");
-		setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "false", 1);
-	}
-
 	status_init_config(&s, git_status_config);
 	argc = parse_options(argc, argv, prefix,
 			     builtin_status_options,
 			     builtin_status_usage, 0);
 	finalize_colopts(&s.colopts, -1);
 	finalize_deferred_config(&s);
 
-	if (no_lock_index)
-		setenv("GIT_LOCK_INDEX", "false", 1);
-	else if (!git_parse_maybe_bool(getenv("GIT_LOCK_INDEX")))
-		no_lock_index = 1;
+	if (no_lock_index) {
+		warning("--no-lock-index is deprecated, use --no-optional-locks"
+			" instead");
+		setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "false", 1);
+	}
 
 	handle_untracked_files_arg(&s);
 	handle_ignored_arg(&s);