ART: Fix UnstartedRuntime unique_ptr braino

Better call reset instead of release.

Bug: 37727233
Test: mma SANITIZE_HOST=address art-boot-image
Change-Id: Ib4f4cce1440bb7accf32e0d93ff8c5a3d2fe8171
diff --git a/runtime/interpreter/unstarted_runtime.cc b/runtime/interpreter/unstarted_runtime.cc
index 70be30c..96934bc 100644
--- a/runtime/interpreter/unstarted_runtime.cc
+++ b/runtime/interpreter/unstarted_runtime.cc
@@ -568,7 +568,7 @@
   // Copy in content.
   memcpy(h_array->GetData(), mem_map->Begin(), map_size);
   // Be proactive releasing memory.
-  mem_map.release();
+  mem_map.reset();
 
   // Create a ByteArrayInputStream.
   Handle<mirror::Class> h_class(hs.NewHandle(