minor: fix ReturnCount checkstyle violations

checkstyle-sonar-plugin/src/main/java/org/sonar/plugins/checkstyle/CheckstyleAuditListener.java

@@ -127,14 +127,16 @@ static String getRuleKey(AuditEvent event) {
 
     @VisibleForTesting
     static String getMessage(AuditEvent event) {
+        String result;
         try {
-            return event.getMessage();
+            result = event.getMessage();
 
         }
         catch (Exception ex) {
             LOG.warn("AuditEvent is created incorrectly. Exception happen during getMessage()", ex);
-            return null;
+            result = null;
         }
+        return result;
     }
 
     @VisibleForTesting

checkstyle-sonar-plugin/src/main/java/org/sonar/plugins/checkstyle/CheckstyleConfiguration.java

@@ -94,10 +94,11 @@ public List<File> getSourceFiles() {
     }
 
     public File getTargetXmlReport() {
+        File result = null;
         if (conf.getBoolean(PROPERTY_GENERATE_XML)) {
-            return new File(fileSystem.workDir(), "checkstyle-result.xml");
+            result = new File(fileSystem.workDir(), "checkstyle-result.xml");
         }
-        return null;
+        return result;
     }
 
     public Configuration getCheckstyleConfiguration() throws CheckstyleException {

checkstyle-sonar-plugin/src/main/java/org/sonar/plugins/checkstyle/CheckstyleProfileImporter.java

@@ -154,12 +154,14 @@ static boolean isIgnored(String configKey) {
 
     @VisibleForTesting
     static boolean isFilter(String configKey) {
+        boolean result = false;
         for (String filter : FILTERS) {
             if (StringUtils.equals(configKey, filter)) {
-                return true;
+                result = true;
+                break;
             }
         }
-        return false;
+        return result;
     }
 
     private void processRule(RulesProfile profile, String path, String moduleName,

checkstyle-sonar-plugin/src/test/java/org/sonar/plugins/checkstyle/internal/CheckUtil.java

@@ -201,16 +201,18 @@ else if (module == RegexpSinglelineCheck.class
      */
     public static String getCheckMessage(Class<?> module, String messageKey,
             Object... arguments) {
+        String result;
         final Properties pr = new Properties();
         try {
             pr.load(module.getResourceAsStream("messages.properties"));
+            final MessageFormat formatter =
+                    new MessageFormat(pr.getProperty(messageKey), Locale.ENGLISH);
+            result = formatter.format(arguments);
         }
         catch (IOException ex) {
-            return null;
+            result = null;
         }
-        final MessageFormat formatter =
-                new MessageFormat(pr.getProperty(messageKey), Locale.ENGLISH);
-        return formatter.format(arguments);
+        return result;
     }
 
     public static String getTokenText(int[] tokens, int... subtractions) {

checkstyle-sonar-plugin/src/test/java/org/sonar/plugins/checkstyle/internal/XmlUtil.java

@@ -41,21 +41,22 @@ private XmlUtil() {
 
     public static Document getRawXml(String fileName, String code, String unserializedSource)
             throws ParserConfigurationException {
+        Document result = null;
         try {
             final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
             factory.setValidating(false);
             factory.setNamespaceAware(true);
 
             final DocumentBuilder builder = factory.newDocumentBuilder();
 
-            return builder.parse(new InputSource(new StringReader(code)));
+            result = builder.parse(new InputSource(new StringReader(code)));
         }
         catch (IOException | SAXException ex) {
             Assert.fail(fileName + " has invalid xml (" + ex.getMessage() + "): "
                     + unserializedSource);
         }
 
-        return null;
+        return result;
     }
 
     public static Set<Node> getChildrenElements(Node node) {