um: irqs: allow invoking time-travel handler multiple times

If we happen to get multiple messages while IRQS are already
suspended, we still need to handle them, since otherwise the
simulation blocks.

Remove the "prevent nesting" part, time_travel_add_irq_event()
will deal with being called multiple times just fine.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/kernel/irq.c

@@ -101,10 +101,12 @@ static bool irq_do_timetravel_handler(struct irq_entry *entry,
 	if (!reg->timetravel_handler)
 		return false;
 
-	/* prevent nesting - we'll get it again later when we SIGIO ourselves */
-	if (reg->pending_on_resume)
-		return true;
-
+	/*
+	 * Handle all messages - we might get multiple even while
+	 * interrupts are already suspended, due to suspend order
+	 * etc. Note that time_travel_add_irq_event() will not add
+	 * an event twice, if it's pending already "first wins".
+	 */
 	reg->timetravel_handler(reg->irq, entry->fd, reg->id, &reg->event);
 
 	if (!reg->event.pending)