ARM: mmp: using for_each_set_bit to simplify the code

Using for_each_set_bit() to simplify the code.

spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>

arch/arm/mach-mmp/irq.c

@@ -153,10 +153,8 @@ static void icu_mux_irq_demux(unsigned int irq, struct irq_desc *desc)
 		status = readl_relaxed(data->reg_status) & ~mask;
 		if (status == 0)
 			break;
-		n = find_first_bit(&status, BITS_PER_LONG);
-		while (n < BITS_PER_LONG) {
+		for_each_set_bit(n, &status, BITS_PER_LONG) {
 			generic_handle_irq(icu_data[i].virq_base + n);
-			n = find_next_bit(&status, BITS_PER_LONG, n + 1);
 		}
 	}
 }