MountService listeners can not be unregistered

When unregistering MountService listeners, their Binder proxy
objects were compared to registered listeners instead of their
backing objects.

Change-Id: Ie98a686b1d17544f1eda59fb3eb0dc02d836c1b2
diff --git a/services/java/com/android/server/MountService.java b/services/java/com/android/server/MountService.java
index e60231a..0d535cc 100644
--- a/services/java/com/android/server/MountService.java
+++ b/services/java/com/android/server/MountService.java
@@ -1411,7 +1411,7 @@
     public void unregisterListener(IMountServiceListener listener) {
         synchronized (mListeners) {
             for(MountServiceBinderListener bl : mListeners) {
-                if (bl.mListener == listener) {
+                if (bl.mListener.asBinder() == listener.asBinder()) {
                     mListeners.remove(mListeners.indexOf(bl));
                     listener.asBinder().unlinkToDeath(bl, 0);
                     return;