Revert "Change LoadNativeLibrary to use GetOrCreateAllocator"

This reverts commit 2d902b99bba7ae1ad77ebeb038a4ef63c3ed6399.

Change-Id: I4a674844f2f6d76d1c33741b46f12417ec7eab35
diff --git a/runtime/java_vm_ext.cc b/runtime/java_vm_ext.cc
index 58da7f2..7cc05f7 100644
--- a/runtime/java_vm_ext.cc
+++ b/runtime/java_vm_ext.cc
@@ -736,7 +736,7 @@
     // it's okay to decode it without worrying about unexpectedly marking it alive.
     mirror::ClassLoader* loader = soa.Decode<mirror::ClassLoader*>(class_loader);
     class_loader_allocator =
-        Runtime::Current()->GetClassLinker()->GetOrCreateAllocatorForClassLoader(loader);
+        Runtime::Current()->GetClassLinker()->GetAllocatorForClassLoader(loader);
     CHECK(class_loader_allocator != nullptr);
   }
   if (library != nullptr) {