surfaceflinger: remove BufferLayerConsumer::mUseFenceSync

BufferLayerConsumer::mUseFenceSync is always false.  As a result, we
can remove EGLSyncKHR from EglSlot and PendingRelease.

Test: boots
Change-Id: I0fec2137a6548335303e990232637b2da00fa3c6
diff --git a/services/surfaceflinger/SurfaceFlingerConsumer.h b/services/surfaceflinger/SurfaceFlingerConsumer.h
index cd13938..7fecd55 100644
--- a/services/surfaceflinger/SurfaceFlingerConsumer.h
+++ b/services/surfaceflinger/SurfaceFlingerConsumer.h
@@ -40,7 +40,7 @@
 
     SurfaceFlingerConsumer(const sp<IGraphicBufferConsumer>& consumer,
             uint32_t tex, Layer* layer)
-        : BufferLayerConsumer(consumer, tex, BufferLayerConsumer::TEXTURE_EXTERNAL, false, false),
+        : BufferLayerConsumer(consumer, tex, BufferLayerConsumer::TEXTURE_EXTERNAL, false),
           mTransformToDisplayInverse(false), mSurfaceDamage(), mLayer(layer)
     {}