Fix core-dump with some games

http://bugs.gentoo.org/102987
http://thread.gmane.org/gmane.comp.emulators.xmame.devel/5314

--- xmame-0.99/src/drivers/mcr3.c
+++ xmame-0.99/src/drivers/mcr3.c
@@ -1083,6 +1083,7 @@
 
 	/* video hardware */
 	MDRV_VIDEO_START(mcrmono)
+        MDRV_VIDEO_UPDATE(mcr3)
 MACHINE_DRIVER_END