[SUREFIRE-1990] The previous XML report should be deleted before new …

…run or re-run

maven-surefire-common/src/main/java/org/apache/maven/plugin/surefire/report/StatelessXmlReporter.java

@@ -346,9 +346,8 @@ private OutputStream getOutputStream( WrappedReportEntry testSetReportEntry )
         throws IOException
     {
         File reportFile = getReportFile( testSetReportEntry );
-
         File reportDir = reportFile.getParentFile();
-
+        reportFile.delete();
         //noinspection ResultOfMethodCallIgnored
         reportDir.mkdirs();
         return new BufferedOutputStream( new FileOutputStream( reportFile ), 64 * 1024 );