Finish off the new JNI implementation.

There are a handful of remaining TODOs, but this gives us complete coverage.

Change-Id: Ibee38e6a87a0fcfae769d991125b0551243c8eeb
diff --git a/src/thread.cc b/src/thread.cc
index 477b149..0878b50 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -175,10 +175,7 @@
       PLOG(FATAL) << "pthread_setspecific failed";
   }
 
-  JavaVMExt* vm = runtime->GetJavaVM();
-  CHECK(vm != NULL);
-  bool check_jni = vm->check_jni;
-  thread->jni_env_ = new JNIEnvExt(thread, check_jni);
+  thread->jni_env_ = new JNIEnvExt(thread, runtime->GetJavaVM());
 
   return thread;
 }