HADOOP-14970. MiniHadoopClusterManager doesn't respect lack of format option. Contributed by Erik Krogen

(cherry picked from commit 1a407bc9906306801690bc75ff0f0456f8f265fd)

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapreduce/MiniHadoopClusterManager.java

@@ -152,7 +152,9 @@ public class MiniHadoopClusterManager {
       URISyntaxException {
     if (!noDFS) {
       dfs = new MiniDFSCluster.Builder(conf).nameNodePort(nnPort)
-          .numDataNodes(numDataNodes).startupOption(dfsOpts).build();
+          .numDataNodes(numDataNodes)
+          .format(dfsOpts == StartupOption.FORMAT)
+          .startupOption(dfsOpts).build();
       LOG.info("Started MiniDFSCluster -- namenode on port "
           + dfs.getNameNodePort());
     }