submodule helper: remove double 'fatal: ' prefix

The prefix is added by die(...), so we don't have to do it.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/submodule--helper.c

@@ -516,13 +516,13 @@ int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
 {
 	int i;
 	if (argc < 2)
-		die(_("fatal: submodule--helper subcommand must be "
+		die(_("submodule--helper subcommand must be "
 		      "called with a subcommand"));
 
 	for (i = 0; i < ARRAY_SIZE(commands); i++)
 		if (!strcmp(argv[1], commands[i].cmd))
 			return commands[i].fn(argc - 1, argv + 1, prefix);
 
-	die(_("fatal: '%s' is not a valid submodule--helper "
+	die(_("'%s' is not a valid submodule--helper "
 	      "subcommand"), argv[1]);
 }