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/src/gpu/GrSWMaskHelper.h b/src/gpu/GrSWMaskHelper.h
index fb5d9e8..d1e1265 100644
--- a/src/gpu/GrSWMaskHelper.h
+++ b/src/gpu/GrSWMaskHelper.h
@@ -67,7 +67,7 @@
 
     // Convert mask generation results to a signed distance field
     void toSDF(unsigned char* sdf);
-    
+
     // Reset the internal bitmap
     void clear(uint8_t alpha) {
         fPixels.erase(SkColorSetARGB(alpha, 0xFF, 0xFF, 0xFF));