Update SkOffsetImageFilter to sk_sp

TBR=reed@google.com

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1842193002

Review URL: https://codereview.chromium.org/1842193002
diff --git a/samplecode/SampleFilterFuzz.cpp b/samplecode/SampleFilterFuzz.cpp
index a1e8c2d..900ae7b 100644
--- a/samplecode/SampleFilterFuzz.cpp
+++ b/samplecode/SampleFilterFuzz.cpp
@@ -605,12 +605,9 @@
                                              nullptr);
         break;
     }
-    case OFFSET: {
-        sk_sp<SkImageFilter> subFilter(make_image_filter());
-        filter = sk_sp<SkImageFilter>(SkOffsetImageFilter::Create(make_scalar(), make_scalar(),
-                                                                  subFilter.get()));
+    case OFFSET:
+        filter = SkOffsetImageFilter::Make(make_scalar(), make_scalar(), make_image_filter());
         break;
-    }
     case MATRIX: {
         sk_sp<SkImageFilter> subFilter(make_image_filter());
         filter = sk_sp<SkImageFilter>(SkImageFilter::CreateMatrixFilter(make_matrix(),