fix for building with Visual Studio (nw)

src/devices/machine/gen_fifo.cpp

@@ -151,7 +151,7 @@ template<typename T> T generic_fifo_device_base<T>::pop()
 	}
 }
 
-template<typename T> void generic_fifo_device_base<T>::push(T &&t)
+template<typename T> void generic_fifo_device_base<T>::push(T t)
 {
 	// Are we already overflowed?
 	if(!m_extra_values.empty())

src/devices/machine/gen_fifo.h

@@ -104,7 +104,7 @@ public:
 
 	/* Generic push/pop */
 	T pop();
-	void push(T &&value);
+	void push(T value);
 
 	/* Indicates whether the fifo is empty or full.  Note that a pop
 	   on a full fifo does not ensure it will become non-full, there