C++11 style fixups

Change-Id: I356d02338820bfef41a9e278c88dafc17cfe1cf9
diff --git a/libs/hwui/renderthread/DrawFrameTask.cpp b/libs/hwui/renderthread/DrawFrameTask.cpp
index 679a00f..f48ee41 100644
--- a/libs/hwui/renderthread/DrawFrameTask.cpp
+++ b/libs/hwui/renderthread/DrawFrameTask.cpp
@@ -114,7 +114,8 @@
 
 bool DrawFrameTask::syncFrameState(TreeInfo& info) {
     ATRACE_CALL();
-    mRenderThread->timeLord().vsyncReceived(mFrameInfo[FrameInfoIndex::kVsync]);
+    int64_t vsync = mFrameInfo[static_cast<int>(FrameInfoIndex::kVsync)];
+    mRenderThread->timeLord().vsyncReceived(vsync);
     mContext->makeCurrent();
     Caches::getInstance().textureCache.resetMarkInUse();