Fix mPreviouslyPresentedLayerStacks leak for bufferless layers

Fix: 295344852
Test: presubmit
Change-Id: Ib906c9002c56b8a7398cfcc2ede4a07be7484ce0
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 0c1c014..da87e8e 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -2941,7 +2941,9 @@
         ch->previousReleaseFences.emplace_back(std::move(futureFenceResult));
         ch->name = mName;
     }
-    mPreviouslyPresentedLayerStacks.push_back(layerStack);
+    if (mBufferInfo.mBuffer) {
+        mPreviouslyPresentedLayerStacks.push_back(layerStack);
+    }
 }
 
 void Layer::onSurfaceFrameCreated(