Style bikeshed - remove extraneous whitespace

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1842753002

Review URL: https://codereview.chromium.org/1842753002
diff --git a/gm/lightingshader.cpp b/gm/lightingshader.cpp
index 6d25671..54f698a 100644
--- a/gm/lightingshader.cpp
+++ b/gm/lightingshader.cpp
@@ -92,7 +92,7 @@
 
         SkMatrix matrix;
         matrix.setRectToRect(bitmapBounds, r, SkMatrix::kFill_ScaleToFit);
-    
+
         const SkMatrix& ctm = canvas->getTotalMatrix();
 
         // TODO: correctly pull out the pure rotation