Java5 optimization

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@15623 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/Functions.java

@@ -178,7 +178,7 @@ public class Functions {
      * Adds the proper suffix.
      */
     public static String addSuffix(int n, String singular, String plural) {
-        StringBuffer buf = new StringBuffer();
+        StringBuilder buf = new StringBuilder();
         buf.append(n).append(' ');
         if(n==1)
             buf.append(singular);