fix a memory corruption where a SF Client could be used after it's been destroyed
diff --git a/libs/surfaceflinger/LayerBuffer.h b/libs/surfaceflinger/LayerBuffer.h
index 22af43e..587d31b 100644
--- a/libs/surfaceflinger/LayerBuffer.h
+++ b/libs/surfaceflinger/LayerBuffer.h
@@ -57,7 +57,7 @@
     virtual uint32_t getTypeInfo() const { return typeInfo; }
 
             LayerBuffer(SurfaceFlinger* flinger, DisplayID display,
-                        Client* client, int32_t i);
+                    const sp<Client>& client, int32_t i);
         virtual ~LayerBuffer();
 
     virtual void onFirstRef();