lguest: remove obsolete LHREQ_BREAK call

We no longer need an efficient mechanism to force the Guest back into
host userspace, as each device is serviced without bothering the main
Guest process (aka. the Launcher).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/include/linux/lguest_launcher.h b/include/linux/lguest_launcher.h
index 9de964b..bfefbdf 100644
--- a/include/linux/lguest_launcher.h
+++ b/include/linux/lguest_launcher.h
@@ -57,7 +57,7 @@
 	LHREQ_INITIALIZE, /* + base, pfnlimit, start */
 	LHREQ_GETDMA, /* No longer used */
 	LHREQ_IRQ, /* + irq */
-	LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
+	LHREQ_BREAK, /* No longer used */
 	LHREQ_EVENTFD, /* + address, fd. */
 };