posix: fifo: use right prototype

Change-Id: Ia6aee61aa7059a70d2014f7de66a41cbaca8c7ed
Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>

posix/JackFifo.h

@@ -44,7 +44,7 @@ class SERVER_EXPORT JackFifo : public detail::JackSynchro
 
     protected:
 
-        void BuildName(const char* name, const char* server_name, char* res);
+        void BuildName(const char* name, const char* server_name, char* res, int size);
 
     public: