Don't log an error on HWC1.1+ devices with no FB HAL

Change-Id: I015e5a1a1f926181e51f82525f69beff71bd70cd
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 92e4cbf..fdbd2d9 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -265,7 +265,7 @@
 
 private:
     void loadHwcModule();
-    void loadFbHalModule();
+    int loadFbHalModule();
 
     LayerListIterator getLayerIterator(int32_t id, size_t index);