Revert "HADOOP-12687. SecureUtil#QualifiedHostResolver#getByName should also try to resolve direct hostname (Sunil G via rohithsharmaks)"

This reverts commit 2b252844e04eebd4f32815d4bd6f914c02994709.

Conflicts:
	hadoop-common-project/hadoop-common/CHANGES.txt

(cherry picked from commit ed18527e38438113fdf2f48b08be5ec283a5f481)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -20,10 +20,6 @@ Release 2.9.0 - UNRELEASED
 
   BUG FIXES
 
-    HADOOP-12687. SecureUtil#QualifiedHostResolver#getByName should also try to
-    resolve direct hostname, incase multiple loopback addresses are present in
-    /etc/hosts (Sunil G via rohithsharmaks)
-
     HADOOP-12655. TestHttpServer.testBindAddress bind port range is wider
     than expected. (Wei-Chiu Chuang via stevel)
 

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/SecurityUtil.java

@@ -580,13 +580,7 @@ public class SecurityUtil {
           addr = getByNameWithSearch(host);
           if (addr == null) {
             addr = getByExactName(host);
-            // If multiple loopback addresses are present, a direct lookup
-            // will be helpful
-            if (addr == null) {
-              addr = InetAddress.getByName(host);
-            }
           }
-
         }
       }
       // unresolvable!