replace StringBuffer by StringBuilder

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1384337 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/maven/plugin/changelog/ChangeLogReport.java b/src/main/java/org/apache/maven/plugin/changelog/ChangeLogReport.java
index d64e3b2..1a6328b 100644
--- a/src/main/java/org/apache/maven/plugin/changelog/ChangeLogReport.java
+++ b/src/main/java/org/apache/maven/plugin/changelog/ChangeLogReport.java
@@ -554,7 +554,7 @@
     private void writeChangelogXml( List changelogList )
         throws FileNotFoundException, UnsupportedEncodingException, IOException
     {
-        StringBuffer changelogXml = new StringBuffer();
+        StringBuilder changelogXml = new StringBuilder();
 
         changelogXml.append( "<?xml version=\"1.0\" encoding=\"" ).append( getOutputEncoding() ).append( "\"?>\n" );
         changelogXml.append( "<changelog>" );