Update calls to IInterface::asBinder()

to use the new static version.

Change-Id: Ia7b10eb38ca55b72278bfd33d3bf647f338b4e6a

Conflicts:
	media/libmedia/IAudioFlinger.cpp
	media/libmedia/IMediaPlayer.cpp
	media/libstagefright/CameraSource.cpp
diff --git a/media/libmediaplayerservice/Drm.cpp b/media/libmediaplayerservice/Drm.cpp
index d222316..89d689d 100644
--- a/media/libmediaplayerservice/Drm.cpp
+++ b/media/libmediaplayerservice/Drm.cpp
@@ -84,10 +84,10 @@
 {
     Mutex::Autolock lock(mEventLock);
     if (mListener != NULL){
-        mListener->asBinder()->unlinkToDeath(this);
+        IInterface::asBinder(mListener)->unlinkToDeath(this);
     }
     if (listener != NULL) {
-        listener->asBinder()->linkToDeath(this);
+        IInterface::asBinder(listener)->linkToDeath(this);
     }
     mListener = listener;
     return NO_ERROR;