fix warings. add SkTAbs()



git-svn-id: http://skia.googlecode.com/svn/trunk@7075 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/Matrix44Test.cpp b/tests/Matrix44Test.cpp
index a680b44..269e359 100644
--- a/tests/Matrix44Test.cpp
+++ b/tests/Matrix44Test.cpp
@@ -25,7 +25,7 @@
     const SkScalar tolerance = SK_Scalar1 / 1024;
 #endif
 
-    return SkScalarAbs(a - b) <= tolerance;
+    return SkTAbs<SkMScalar>(a - b) <= tolerance;
 }
 
 template <typename T> void assert16(skiatest::Reporter* reporter, const T data[],