Update calls to IInterface::asBinder()

to use the new static version.

Change-Id: I89a5988a0ac694ffc04d88cf939e8455bf925d4c
diff --git a/media/libmedia/mediametadataretriever.cpp b/media/libmedia/mediametadataretriever.cpp
index 39a239d..8e8a1ed 100644
--- a/media/libmedia/mediametadataretriever.cpp
+++ b/media/libmedia/mediametadataretriever.cpp
@@ -172,7 +172,7 @@
 {
     Mutex::Autolock lock(sServiceLock);
     if (sService != 0) {
-        sService->asBinder()->unlinkToDeath(this);
+        IInterface::asBinder(sService)->unlinkToDeath(this);
     }
 }