Fix return value in read pixels unit test



git-svn-id: http://skia.googlecode.com/svn/trunk@2656 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/ReadPixelsTest.cpp b/tests/ReadPixelsTest.cpp
index 026694f..088aff2 100644
--- a/tests/ReadPixelsTest.cpp
+++ b/tests/ReadPixelsTest.cpp
@@ -205,7 +205,7 @@
             }
         }
     }
-    return failed;
+    return !failed;
 }
 
 enum BitmapInit {