RANGER-5181:Assigned parameter values to instance variables (#705)

diff --git a/unixauthclient/src/main/java/org/apache/ranger/authentication/unix/jaas/PamLoginModule.java b/unixauthclient/src/main/java/org/apache/ranger/authentication/unix/jaas/PamLoginModule.java
index 84d8a7f..9166ef0 100644
--- a/unixauthclient/src/main/java/org/apache/ranger/authentication/unix/jaas/PamLoginModule.java
+++ b/unixauthclient/src/main/java/org/apache/ranger/authentication/unix/jaas/PamLoginModule.java
@@ -61,9 +61,9 @@ public PamLoginModule() {
 
     @Override
     public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState, Map<String, ?> options) {
-        subject         = subject;
-        callbackHandler = callbackHandler;
-        options         = new HashMap<>(options);
+        this.subject         = subject;
+        this.callbackHandler = callbackHandler;
+        this.options         = new HashMap<>(options);
     }
 
     @Override