return false if we can't scale, to force us to try to lock the original and then proceed

BUG=
R=wangxianzhu@chromium.org

Review URL: https://codereview.chromium.org/27382002

git-svn-id: http://skia.googlecode.com/svn/trunk/src@11789 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/core/SkBitmapProcState.cpp b/core/SkBitmapProcState.cpp
index 2b0e557..69af8b9 100644
--- a/core/SkBitmapProcState.cpp
+++ b/core/SkBitmapProcState.cpp
@@ -150,7 +150,7 @@
                                         simd)) {
                 // we failed to create fScaledBitmap, so just return and let
                 // the scanline proc handle it.
-                return true;
+                return false;
 
             }
             fScaledCacheID = SkScaledImageCache::AddAndLock(fOrigBitmap,