freetdm: windows unref parameter

libs/freetdm/src/ftdm_io.c

@@ -2005,6 +2005,11 @@ FT_DECLARE(ftdm_status_t) _ftdm_channel_call_place(const char *file, const char
 	} else {
 		ftdm_log(FTDM_LOG_ERROR, "outgoing_call method not implemented in this span!\n");
 	}
+#ifdef __WINDOWS__
+	UNREFERENCED_PARAMETER(file);
+	UNREFERENCED_PARAMETER(func);
+	UNREFERENCED_PARAMETER(line);
+#endif
 	return FTDM_FAIL;
 }