fix warnings

git-svn-id: http://skia.googlecode.com/svn/trunk@1129 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleTextEffects.cpp b/samplecode/SampleTextEffects.cpp
index 77a3bd7..bd134d0 100644
--- a/samplecode/SampleTextEffects.cpp
+++ b/samplecode/SampleTextEffects.cpp
@@ -17,7 +17,7 @@
     unsigned g = SkGetPackedG32(c);
     unsigned b = SkGetPackedB32(c);
 
-    unsigned x = r * 5 + g * 7 + b * 4 >> 4;
+    unsigned x = (r * 5 + g * 7 + b * 4) >> 4;
 
     return SkPackARGB32(0, x, x, x) | (c & (SK_A32_MASK << SK_A32_SHIFT));
 }