Clean up useless comments in SkScaledImageCache.h

BUG=skia:
R=reed@google.com

Author: qiankun.miao@intel.com

Review URL: https://codereview.chromium.org/499203002
diff --git a/src/core/SkBitmapCache.cpp b/src/core/SkBitmapCache.cpp
index de52b63..1713fe4 100644
--- a/src/core/SkBitmapCache.cpp
+++ b/src/core/SkBitmapCache.cpp
@@ -32,7 +32,7 @@
     {
         this->init(sizeof(fGenID) + sizeof(fScaleX) + sizeof(fScaleY) + sizeof(fBounds));
     }
-    
+
     uint32_t    fGenID;
     SkScalar    fScaleX;
     SkScalar    fScaleY;