Fix the string we're checking for in the #if defined(), so that loops actually do get unrolled on Windows (15% perf win claimed many months ago).

http://codereview.appspot.com/5528078



git-svn-id: http://skia.googlecode.com/svn/trunk@3019 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/SkBlurMask.cpp b/src/effects/SkBlurMask.cpp
index 79fbcf7..95a1e6b 100644
--- a/src/effects/SkBlurMask.cpp
+++ b/src/effects/SkBlurMask.cpp
@@ -16,7 +16,7 @@
 // breakeven on Mac, and ~15% slowdown on Linux.
 // Reading a word at a time when bulding the sum buffer seems to give
 // us no appreciable speedup on Windows or Mac, and 2% slowdown on Linux.
-#if defined(BUILD_FOR_WIN_32)
+#if defined(SK_BUILD_FOR_WIN32)
 #define UNROLL_KERNEL_LOOP 1
 #endif