Make sure no error message is printed when pthread_mutex_trylock() is called on a non-recursive mutex from the thread that holds a lock on the mutex.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7769 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/exp-drd/drd_clientreq.h b/exp-drd/drd_clientreq.h
index 8d421d6..3657319 100644
--- a/exp-drd/drd_clientreq.h
+++ b/exp-drd/drd_clientreq.h
@@ -57,7 +57,7 @@
   /* args: Addr, MutexT */
   /* to notify the drd tool of pthread_mutex_lock calls */
   VG_USERREQ__PRE_MUTEX_LOCK,
-  /* args: Addr, MutexT */
+  /* args: Addr, MutexT, Bool */
   /* to notify the drd tool of pthread_mutex_lock calls */
   VG_USERREQ__POST_MUTEX_LOCK,
   /* args: Addr, Bool */