64-bit build fix.

sizeof vs jlong comparison.

Change-Id: I6d9377e71169911201b2342d914ac014eb9c0b4a
diff --git a/runtime/jni_internal_test.cc b/runtime/jni_internal_test.cc
index 709530e..83e9b10 100644
--- a/runtime/jni_internal_test.cc
+++ b/runtime/jni_internal_test.cc
@@ -1497,7 +1497,7 @@
   ASSERT_NE(buffer, nullptr);
   ASSERT_TRUE(env_->IsInstanceOf(buffer, buffer_class));
   ASSERT_EQ(env_->GetDirectBufferAddress(buffer), bytes);
-  ASSERT_EQ(env_->GetDirectBufferCapacity(buffer), sizeof(bytes));
+  ASSERT_EQ(env_->GetDirectBufferCapacity(buffer), static_cast<jlong>(sizeof(bytes)));
 }
 
 TEST_F(JniInternalTest, MonitorEnterExit) {