Bug 1431028 - Move the gfx warning to the correct position. r=mattwoodrow

We should only show the warning message when we have the on-white buffer.

MozReview-Commit-ID: 4gzo0reYIVL

gfx/layers/client/SingleTiledContentClient.cpp

@@ -242,9 +242,9 @@ ClientSingleTiledLayerBuffer::PaintThebes(const nsIntRegion& aNewValidRegion,
                   copy.CopyBuffer();
                 }
               }
+            } else {
+              gfxWarning() << "[Tiling:Client] Failed to aquire the discarded front buffer's draw target";
             }
-          } else {
-            gfxWarning() << "[Tiling:Client] Failed to aquire the discarded front buffer's draw target";
           }
         } else {
           gfxWarning() << "[Tiling:Client] Failed to aquire the discarded front buffer's draw target";