ART: Fix double-free in oatdump

The ImageDumper doesn't own the OatDumperOptions.

Bug: 20818721
Change-Id: Iea11ada8fb6418b226d39b33c252a834c42e655e
diff --git a/oatdump/oatdump.cc b/oatdump/oatdump.cc
index b9a3d37..949c2cb 100644
--- a/oatdump/oatdump.cc
+++ b/oatdump/oatdump.cc
@@ -2092,7 +2092,7 @@
   gc::space::ImageSpace& image_space_;
   const ImageHeader& image_header_;
   std::unique_ptr<OatDumper> oat_dumper_;
-  std::unique_ptr<OatDumperOptions> oat_dumper_options_;
+  OatDumperOptions* oat_dumper_options_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageDumper);
 };