Mac 10.6 compiler fix for r12665 (Remove duplicate impl for SkImageInfo flattening)

https://codereview.chromium.org/101913006/



git-svn-id: http://skia.googlecode.com/svn/trunk/src@12666 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/lazy/SkDiscardablePixelRef.cpp b/lazy/SkDiscardablePixelRef.cpp
index dde48e5..77ac825 100644
--- a/lazy/SkDiscardablePixelRef.cpp
+++ b/lazy/SkDiscardablePixelRef.cpp
@@ -63,7 +63,7 @@
         fDiscardableMemory->unlock();
         SkDELETE(fDiscardableMemory);
         fDiscardableMemory = NULL;
-        return NULL;
+        return false;
     }
 
     rec->fPixels = pixels;