Don't keep queueing work indefinitely if we're in opt failover mode.
diff --git a/cgminer.c b/cgminer.c
index a39a83b..1449617 100644
--- a/cgminer.c
+++ b/cgminer.c
@@ -2409,7 +2409,7 @@ static void *get_work_thread(void *userdata)
mutex_unlock(stgd_lock);
if (((cs >= opt_queue || cq >= opt_queue) && ts >= maxq) ||
- ((cs >= opt_queue || cq >= opt_queue) && tq >= maxq && cq < maxq) ||
+ ((cs >= opt_queue || cq >= opt_queue) && tq >= maxq && ((cq < maxq && !opt_fail_only) || opt_fail_only)) ||
clone_available())
goto out;