Fix bug introduced by earlier "cleanup".

src/messages.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 39 matching lines @@
 
 var kReplacementMarkers = [ "%0", "%1", "%2", "%3" ];
 
 function FormatString(format, message) {
   var args = %MessageGetArguments(message);
   var result = "";
   var arg_num = 0;
   for (var i = 0; i < format.length; i++) {
     var str = format[i];
     for (arg_num = 0; arg_num < kReplacementMarkers.length; arg_num++) {
-      if (str !== kReplacementMarkers[arg_num]) continue;
-      try {
-        str = ToDetailString(args[arg_num]);
-      } catch (e) {
-        str = "#<error>";
+      if (str == kReplacementMarkers[arg_num]) {
+        try {
+          str = ToDetailString(args[arg_num]);
+        } catch (e) {
+          str = "#<error>";
+        }
+        break;
       }
     }
     result += str;
   }
   return result;
 }
 
 
 // To check if something is a native error we need to check the
 // concrete native error types. It is not enough to check "obj
@@ skipping 1064 matching lines @@
     throw e;
   }
 }
 
 
 InstallFunctions($Error.prototype, DONT_ENUM, ['toString', errorToString]);
 
 // Boilerplate for exceptions for stack overflows. Used from
 // Isolate::StackOverflow().
 const kStackOverflowBoilerplate = MakeRangeError('stack_overflow', []);