branch: error code with --edit-description

Since c2d17ba (branch --edit-description: protect against mistyped
branch name, 2012-02-05) we return -1 on error editing the branch
description.

Let's change to 1, which follows the established convention and it is
better for portability reasons.

Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: rjusto

builtin/branch.c

@@ -816,7 +816,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 
 		strbuf_addf(&branch_ref, "refs/heads/%s", branch_name);
 		if (!ref_exists(branch_ref.buf))
-			ret = error((!argc || !strcmp(head, branch_name))
+			error((!argc || !strcmp(head, branch_name))
 			      ? _("No commit on branch '%s' yet.")
 			      : _("No branch named '%s'."),
 			      branch_name);

t/t3200-branch.sh

@@ -1383,7 +1383,7 @@ test_expect_success 'branch --delete --force removes dangling branch' '
 
 test_expect_success 'use --edit-description' '
 	EDITOR=: git branch --edit-description &&
-	test_must_fail git config branch.main.description &&
+	test_expect_code 1 git config branch.main.description &&
 
 	write_script editor <<-\EOF &&
 		echo "New contents" >"$1"