DrmListener: Don't leak memory in error case.

Change-Id: If4dc869e468f52997be732d03dc010f89551cd87
diff --git a/media/ndk/NdkMediaDrm.cpp b/media/ndk/NdkMediaDrm.cpp
index be71f43..8d34ab0 100644
--- a/media/ndk/NdkMediaDrm.cpp
+++ b/media/ndk/NdkMediaDrm.cpp
@@ -99,11 +99,12 @@
             break;
         default:
             ALOGE("Invalid event DrmPlugin::EventType %d, ignored", (int)eventType);
-            return;
+            goto cleanup;
     }
 
     (*mListener)(mObj, &sessionId, ndkEventType, extra, data, dataSize);
 
+ cleanup:
     delete [] sessionId.ptr;
     delete [] data;
 }