Fix initialization order warning.

Change-Id: I794dfaaa3a2f2645a89abc6c45de5f76e485f7d0
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 4afe905..7a69097 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -52,6 +52,7 @@
 Layer::Layer(SurfaceFlinger* flinger,
         DisplayID display, const sp<Client>& client)
     :   LayerBaseClient(flinger, display, client),
+        mFormat(PIXEL_FORMAT_NONE),
         mGLExtensions(GLExtensions::getInstance()),
         mNeedsBlending(true),
         mNeedsDithering(false),
@@ -59,7 +60,7 @@
         mProtectedByApp(false),
         mTextureManager(),
         mBufferManager(mTextureManager),
-        mWidth(0), mHeight(0), mFormat(PIXEL_FORMAT_NONE),
+        mWidth(0), mHeight(0),
         mNeedsScaling(false), mFixedSize(false)
 {
 }