Fix return value of AtomicMethodRefMap::Get()

Test: m test-art-host
Change-Id: I3f0841af081194f56b5f5004f9bd86fa2ab34238
diff --git a/compiler/utils/atomic_method_ref_map-inl.h b/compiler/utils/atomic_method_ref_map-inl.h
index d71c2fe..ad3a099 100644
--- a/compiler/utils/atomic_method_ref_map-inl.h
+++ b/compiler/utils/atomic_method_ref_map-inl.h
@@ -42,7 +42,7 @@
 inline bool AtomicMethodRefMap<T>::Get(MethodReference ref, T* out) const {
   const ElementArray* const array = GetArray(ref.dex_file);
   if (array == nullptr) {
-    return kInsertResultInvalidDexFile;
+    return false;
   }
   *out = (*array)[ref.dex_method_index].LoadRelaxed();
   return true;