Fix pthread_setname_np's behavior on invalid pthread_ts.

Change-Id: I0a154beaab4d164ac812f2564d12e4d79b80a8e8
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 98bc4e5..a86cadc 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -239,7 +239,7 @@
   MakeDeadThread(dead_thread);
 
   // Call pthread_setname_np after thread has already exited.
-  ASSERT_EQ(ENOENT, pthread_setname_np(dead_thread, "short 3"));
+  ASSERT_EQ(ESRCH, pthread_setname_np(dead_thread, "short 3"));
 }
 #endif