Fix checkstyle violations in samples

spring-boot-samples/spring-boot-sample-war/src/main/java/sample/war/SampleWarApplication.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,11 +21,8 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.web.support.SpringBootServletInitializer;
 import org.springframework.context.annotation.PropertySource;
 
-/**
- * Sample WAR application
- */
 @SpringBootApplication
-@PropertySource(value = { "WEB-INF/custom.properties" })
+@PropertySource("WEB-INF/custom.properties")
 public class SampleWarApplication extends SpringBootServletInitializer {
 
 	public static void main(String[] args) {