bisect--helper: retire `--bisect-next-check` subcommand

After reimplementation of `git bisect run` in C,
`--bisect-next-check` subcommand is not needed anymore.

Let's remove it from options list and code.

Mentored by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/bisect--helper.c

@@ -22,7 +22,6 @@ static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN")
 
 static const char * const git_bisect_helper_usage[] = {
 	N_("git bisect--helper --bisect-reset [<commit>]"),
-	N_("git bisect--helper --bisect-next-check <good_term> <bad_term> [<term>]"),
 	N_("git bisect--helper --bisect-terms [--term-good | --term-old | --term-bad | --term-new]"),
 	N_("git bisect--helper --bisect-start [--term-{new,bad}=<term> --term-{old,good}=<term>]"
 					    " [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<paths>...]"),
@@ -1230,12 +1229,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 			return error(_("--bisect-reset requires either no argument or a commit"));
 		res = bisect_reset(argc ? argv[0] : NULL);
 		break;
-	case BISECT_NEXT_CHECK:
-		if (argc != 2 && argc != 3)
-			return error(_("--bisect-next-check requires 2 or 3 arguments"));
-		set_terms(&terms, argv[1], argv[0]);
-		res = bisect_next_check(&terms, argc == 3 ? argv[2] : NULL);
-		break;
 	case BISECT_TERMS:
 		if (argc > 1)
 			return error(_("--bisect-terms requires 0 or 1 argument"));