hpet: use for_each_set_bit()

Replace open-coded loop with for_each_set_bit().
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/char/hpet.c

@@ -215,9 +215,7 @@ static void hpet_timer_set_irq(struct hpet_dev *devp)
 	else
 		v &= ~0xffff;
 
-	for (irq = find_first_bit(&v, HPET_MAX_IRQ); irq < HPET_MAX_IRQ;
-		irq = find_next_bit(&v, HPET_MAX_IRQ, 1 + irq)) {
-
+	for_each_set_bit(irq, &v, HPET_MAX_IRQ) {
 		if (irq >= nr_irqs) {
 			irq = HPET_MAX_IRQ;
 			break;