Expand _01 half<->float limitation to _finite. Simplify.

src/core/SkLinearBitmapPipeline_sample.h

Index: src/core/SkLinearBitmapPipeline_sample.h
diff --git a/src/core/SkLinearBitmapPipeline_sample.h b/src/core/SkLinearBitmapPipeline_sample.h
index 39400f67500bc95986135123d5ffe3970098e54e..e957ae7e4d0268cc285b193d0ceb2d31f9184d47 100644
--- a/src/core/SkLinearBitmapPipeline_sample.h
+++ b/src/core/SkLinearBitmapPipeline_sample.h
@@ -198,7 +198,7 @@ public:
     PixelConverter(const SkPixmap& srcPixmap) { }
 
     Sk4f toSk4f(const Element pixel) const {
-        return SkHalfToFloat_01(pixel);
+        return SkHalfToFloat_finite(pixel);
     }
 };