Update MagnifierImageFilter to sk_sp

TBR=reed@google.com

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1864843002

Review URL: https://codereview.chromium.org/1864843002
diff --git a/samplecode/SampleFilterFuzz.cpp b/samplecode/SampleFilterFuzz.cpp
index 8f83c3e..a7f4163 100644
--- a/samplecode/SampleFilterFuzz.cpp
+++ b/samplecode/SampleFilterFuzz.cpp
@@ -582,8 +582,9 @@
                                          make_image_filter());
         break;
     case MAGNIFIER:
-        filter = sk_sp<SkImageFilter>(SkMagnifierImageFilter::Create(make_rect(), 
-                                                                     make_scalar(true)));
+        filter = SkMagnifierImageFilter::Make(make_rect(),
+                                              make_scalar(true),
+                                              make_image_filter());
         break;
     case DOWN_SAMPLE:
         filter = SkDownSampleImageFilter::Make(make_scalar(), make_image_filter());