Modified GetEventHandles of listener

Now using nCount as in and out argument.
When called, set nCount to the number of available handles.
This value is checked and an error returned, if not enough
handles are available.

server/Sample/sfreerdp.c

@@ -744,7 +744,7 @@ static void test_server_mainloop(freerdp_listener* instance)
 
 	while (1)
 	{
-		count = 0;
+		count = 32;
 
 		if (instance->GetEventHandles(instance, handles, &count))
 		{