Track change of IInterface::asBinder from instance method to static method

Change-Id: Iee262d4223ec3c61dab5ca8d9d7e4a14795da1c3
diff --git a/media/libstagefright/foundation/AWakeLock.cpp b/media/libstagefright/foundation/AWakeLock.cpp
index 88c4f6e..d9277ac 100644
--- a/media/libstagefright/foundation/AWakeLock.cpp
+++ b/media/libstagefright/foundation/AWakeLock.cpp
@@ -36,7 +36,7 @@
 
 AWakeLock::~AWakeLock() {
     if (mPowerManager != NULL) {
-        sp<IBinder> binder = mPowerManager->asBinder();
+        sp<IBinder> binder = IInterface::asBinder(mPowerManager);
         binder->unlinkToDeath(mDeathRecipient);
     }
     clearPowerManager();