move reinterpret_cast into SK_PREFETCH

src/opts/SkBlurImageFilter_opts.h

Index: src/opts/SkBlurImageFilter_opts.h
diff --git a/src/opts/SkBlurImageFilter_opts.h b/src/opts/SkBlurImageFilter_opts.h
index 7844e9fb472ba7f52f0b43a8e0ceadf71ec80427..5633e2ee6fa88d8eceeb07ed729740e2661efe4f 100644
--- a/src/opts/SkBlurImageFilter_opts.h
+++ b/src/opts/SkBlurImageFilter_opts.h
@@ -209,7 +209,7 @@ static void box_blur(const SkPMColor* src, int srcStride, SkPMColor* dst, int ke
             }
             sptr += srcStrideX;
             if (srcDirection == BlurDirection::kY) {
-                SK_PREFETCH(reinterpret_cast<const char*>(sptr + (rightOffset + 1) * srcStrideX));
+                SK_PREFETCH(sptr + (rightOffset + 1) * srcStrideX);
             }
             dptr += dstStrideX;
         }