fix a problem where all hwc layers would have the SKIP flags set

the problem was that LayerBase::setPerFrameData() was always setting
this flag. in fact there was no reason to do this at that point since
the layer is initialized to a default state in setGeometry().

Bug: 7111259
Change-Id: Ib37b0dd7391a6163070e9aca025512159c1705f9

services/surfaceflinger/DisplayHardware/HWComposer.cpp

@@ -546,6 +546,7 @@ public:
         getLayer()->compositionType = HWC_FRAMEBUFFER;
         getLayer()->hints = 0;
         getLayer()->flags = HWC_SKIP_LAYER;
+        getLayer()->handle = 0;
         getLayer()->transform = 0;
         getLayer()->blending = HWC_BLENDING_NONE;
         getLayer()->visibleRegionScreen.numRects = 0;

services/surfaceflinger/LayerBase.cpp

@@ -292,7 +292,6 @@ void LayerBase::setGeometry(
 
 void LayerBase::setPerFrameData(const sp<const DisplayDevice>& hw,
         HWComposer::HWCLayerInterface& layer) {
-    layer.setBuffer(0);
     // we have to set the visible region on every frame because
     // we currently free it during onLayerDisplayed(), which is called
     // after HWComposer::commit() -- every frame.