[ALSA] Fix schedule_timeout usage

Use schedule_timeout_{,un}interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size.  Also use
human-time conversion functions instead of hard-coded division to avoid
rounding issues.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/isa/wavefront/wavefront_synth.c

@@ -275,8 +275,7 @@ static int
 wavefront_sleep (int limit)
 
 {
-	set_current_state(TASK_INTERRUPTIBLE);
-	schedule_timeout(limit);
+	schedule_timeout_interruptible(limit);
 
 	return signal_pending(current);
 }
@@ -1788,8 +1787,7 @@ wavefront_should_cause_interrupt (snd_wavefront_t *dev,
 	outb (val,port);
 	spin_unlock_irq(&dev->irq_lock);
 	while (1) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if ((timeout = schedule_timeout(timeout)) == 0)
+		if ((timeout = schedule_timeout_interruptible(timeout)) == 0)
 			return;
 		if (dev->irq_ok)
 			return;