SF: tidy comments for luma sampling.

Tidying of const, comment and one internal fn name for
Region Luma sampling.

Test: libgui_test --gtest_filter="RegionSamp*"

Change-Id: I46895c8ed5b2e2045d7ce7444085585b62b5ab6e
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 31b4fb6..deb7870 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -635,8 +635,8 @@
     status_t captureScreenCommon(RenderArea& renderArea, TraverseLayersFunction traverseLayers,
                                  sp<GraphicBuffer>* outBuffer, const ui::PixelFormat reqPixelFormat,
                                  bool useIdentityTransform);
-    status_t captureScreenCore(RenderArea& renderArea, TraverseLayersFunction traverseLayers,
-                               const sp<GraphicBuffer>& buffer, bool useIdentityTransform);
+    status_t captureScreenCommon(RenderArea& renderArea, TraverseLayersFunction traverseLayers,
+                                 const sp<GraphicBuffer>& buffer, bool useIdentityTransform);
     status_t captureScreenImplLocked(const RenderArea& renderArea,
                                      TraverseLayersFunction traverseLayers,
                                      ANativeWindowBuffer* buffer, bool useIdentityTransform,