Use kSubpixelRounding in one missed location.

The kSubpixelRounding macro was created to clarify a block of code,
but one simplification was missed.

Review URL: https://codereview.chromium.org/1733843002
diff --git a/src/core/SkFindAndPlaceGlyph.h b/src/core/SkFindAndPlaceGlyph.h
index c74a982..78a02c0 100644
--- a/src/core/SkFindAndPlaceGlyph.h
+++ b/src/core/SkFindAndPlaceGlyph.h
@@ -367,7 +367,7 @@
     static SkPoint SubpixelPositionRounding(SkAxisAlignment axisAlignment) {
         switch (axisAlignment) {
             case kX_SkAxisAlignment:
-                return {SkFixedToScalar(SkGlyph::kSubpixelRound), SK_ScalarHalf};
+                return {kSubpixelRounding, SK_ScalarHalf};
             case kY_SkAxisAlignment:
                 return {SK_ScalarHalf, kSubpixelRounding};
             case kNone_SkAxisAlignment: