HDFS-2572. Remove Unnecessary double-check in DN#getHostName (harsh)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1204177 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -55,6 +55,8 @@ Trunk (unreleased changes)
     HDFS-2564. Cleanup unnecessary exceptions thrown and unnecessary casts.
     (Hari Mankude via eli)
 
+    HDFS-2572. Remove unnecessary double-check in DN#getHostName. (harsh)
+
   OPTIMIZATIONS
     HDFS-2477. Optimize computing the diff between a block report and the
                namenode state. (Tomasz Nykiel via hairong)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -454,11 +454,8 @@ public class DataNode extends Configured
 
   private static String getHostName(Configuration config)
       throws UnknownHostException {
-    String name = null;
     // use configured nameserver & interface to get local hostname
-    if (config.get(DFS_DATANODE_HOST_NAME_KEY) != null) {
-      name = config.get(DFS_DATANODE_HOST_NAME_KEY);
-    }
+    String name = config.get(DFS_DATANODE_HOST_NAME_KEY);
     if (name == null) {
       name = DNS
           .getDefaultHost(config.get(DFS_DATANODE_DNS_INTERFACE_KEY,