[S390] irq change improvements.

Remove the last few places where a pointer to pt_regs gets passed.
Also make sure we call set_irq_regs() before irq_enter() and after
irq_exit(). This doesn't fix anything but makes sure s390 looks the
same like all other architectures.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 1d7d393..21baaf5 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -209,11 +209,11 @@
  * Do the callback functions of expired vtimer events.
  * Called from within the interrupt handler.
  */
-static void do_callbacks(struct list_head *cb_list, struct pt_regs *regs)
+static void do_callbacks(struct list_head *cb_list)
 {
 	struct vtimer_queue *vt_list;
 	struct vtimer_list *event, *tmp;
-	void (*fn)(unsigned long, struct pt_regs*);
+	void (*fn)(unsigned long);
 	unsigned long data;
 
 	if (list_empty(cb_list))
@@ -224,7 +224,7 @@
 	list_for_each_entry_safe(event, tmp, cb_list, entry) {
 		fn = event->function;
 		data = event->data;
-		fn(data, regs);
+		fn(data);
 
 		if (!event->interval)
 			/* delete one shot timer */
@@ -275,7 +275,7 @@
 		list_move_tail(&event->entry, &cb_list);
 	}
 	spin_unlock(&vt_list->lock);
-	do_callbacks(&cb_list, get_irq_regs());
+	do_callbacks(&cb_list);
 
 	/* next event is first in list */
 	spin_lock(&vt_list->lock);