Remove proxy logic from GetCodeItem

TODO: Fix places where this doesn't work. Seems maybe in debugger,
etc.

Bug: 17939199
Change-Id: I1dd3c1b071dc37aa1d0a6c187848978588248617
diff --git a/runtime/mirror/art_method-inl.h b/runtime/mirror/art_method-inl.h
index c29276a..c1f619c 100644
--- a/runtime/mirror/art_method-inl.h
+++ b/runtime/mirror/art_method-inl.h
@@ -380,8 +380,7 @@
 }
 
 inline const DexFile::CodeItem* ArtMethod::GetCodeItem() {
-  mirror::ArtMethod* method = GetInterfaceMethodIfProxy();
-  return method->GetDexFile()->GetCodeItem(method->GetCodeItemOffset());
+  return GetDeclaringClass()->GetDexFile().GetCodeItem(GetCodeItemOffset());
 }
 
 inline bool ArtMethod::IsResolvedTypeIdx(uint16_t type_idx) {