Fix incorrect parameter passing.

git-svn-id: https://pmd.svn.sourceforge.net/svnroot/pmd/trunk@6577 51baf565-9d33-0410-a72c-fc3788e3496d

pmd/regress/test/net/sourceforge/pmd/ReportTest.java

@@ -236,7 +236,7 @@ public class ReportTest extends RuleTst implements ReportListener {
         StringWriter writer = new StringWriter();
         renderer.setWriter(writer);
         renderer.start();
-        renderer.renderFileReport(null);
+        renderer.renderFileReport(report);
         renderer.end();
         return writer.toString();
     }