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/SkGr.cpp b/src/gpu/SkGr.cpp
index 71d9e62..905af81 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -609,7 +609,7 @@
     SkASSERT(!grPaint->getXPFactory());
     SkXfermode* xfermode = skPaint.getXfermode();
     if (xfermode) {
-        // SafeUnref in case a new xfermode is added that returns null. 
+        // SafeUnref in case a new xfermode is added that returns null.
         // In such cases we will fall back to kSrcOver_Mode.
         SkSafeUnref(grPaint->setXPFactory(xfermode->asXPFactory()));
     }