CLOUDSTACK-8607 - Make sure the new password replaces the old one in the queue

- Added log info to show details of the operation
   - Renamed the addPwdToQueue to replaceOldPasswdInQueue

plugins/hypervisors/xenserver/src/com/cloud/hypervisor/xenserver/resource/CitrixResourceBase.java

@@ -271,8 +271,17 @@ public abstract class CitrixResourceBase implements ServerResource, HypervisorRe
     public CitrixResourceBase() {
     }
 
-    public void addToPwdQueue(final String password) {
+    /**
+     * Replaces the old password with the new password used to connect to the host.
+     *
+     * @param password  - the new host password.
+     * @return the old password.
+     */
+    public String replaceOldPasswdInQueue(final String password) {
+        final String oldPasswd = _password.poll();
         _password.add(password);
+
+        return oldPasswd;
     }
 
     public String getPwdFromQueue() {

plugins/hypervisors/xenserver/src/com/cloud/hypervisor/xenserver/resource/wrapper/xenbase/CitrixUpdateHostPasswordCommandWrapper.java

@@ -58,8 +58,8 @@ public final class CitrixUpdateHostPasswordCommandWrapper extends CommandWrapper
         } catch (final Exception e) {
             return new Answer(command, false, e.getMessage());
         }
-        // Add new password to the stack.
-        citrixResourceBase.addToPwdQueue(command.getNewPassword());
+        // Add new password to the queue.
+        citrixResourceBase.replaceOldPasswdInQueue(newPassword);
         return new Answer(command, result.first(), result.second());
     }
 }

server/src/com/cloud/resource/ResourceManagerImpl.java

@@ -2240,6 +2240,8 @@ public class ResourceManagerImpl extends ManagerBase implements ResourceManager,
 
         final UpdateHostPasswordCommand cmd = new UpdateHostPasswordCommand(username, password, hostIpAddress);
         final Answer answer = _agentMgr.easySend(hostId, cmd);
+
+        s_logger.info("Result returned from update host password ==> " + answer.getDetails());
         return answer.getResult();
     }