threading: use correct mutex name in reverse_lock fatal error messages

Now that REVERSE_LOCK requires the name of the actual mutex, it can be used for
better error messages.

Author: theuni

src/sync.h

@@ -248,7 +248,7 @@ class SCOPED_LOCKABLE UniqueLock : public MutexType::unique_lock
 // it is not possible to use the lock's copy of the mutex for that purpose.
 // Instead, the original mutex needs to be passed back to the reverse_lock for
 // the sake of thread-safety analysis, but it is not actually used otherwise.
-#define REVERSE_LOCK(g, cs) typename std::decay<decltype(g)>::type::reverse_lock UNIQUE_NAME(revlock)(g, cs, #g, __FILE__, __LINE__)
+#define REVERSE_LOCK(g, cs) typename std::decay<decltype(g)>::type::reverse_lock UNIQUE_NAME(revlock)(g, cs, #cs, __FILE__, __LINE__)
 
 // When locking a Mutex, require negative capability to ensure the lock
 // is not already held