libbinder: rpc java detach error code

Bug: N/A
Change-Id: I074cefd859f1967a662bdda71f285a60a4bc3cad
Test: N/A
diff --git a/libs/binder/RpcSession.cpp b/libs/binder/RpcSession.cpp
index 7d6bcfc..8bced35 100644
--- a/libs/binder/RpcSession.cpp
+++ b/libs/binder/RpcSession.cpp
@@ -408,10 +408,11 @@
                             "Unable to detach thread. No JavaVM, but it was present before!");
 
         LOG_RPC_DETAIL("Detaching current thread from JVM");
-        if (vm->DetachCurrentThread() != JNI_OK) {
+        int ret = vm->DetachCurrentThread();
+        if (ret == JNI_OK) {
             mAttached = false;
         } else {
-            ALOGW("Unable to detach current thread from JVM");
+            ALOGW("Unable to detach current thread from JVM (%d)", ret);
         }
     }