irq: simplify for_each_irq_desc() usage

Impact: cleanup

all for_each_irq_desc() usage point have !desc check.
then its check can move into for_each_irq_desc() macro.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/irqnr.h b/include/linux/irqnr.h
index c4a59c7..5504a5c 100644
--- a/include/linux/irqnr.h
+++ b/include/linux/irqnr.h
@@ -22,10 +22,14 @@
 
 # define for_each_irq_desc(irq, desc)					\
 	for (irq = 0, desc = irq_to_desc(irq); irq < nr_irqs;		\
-	     irq++, desc = irq_to_desc(irq))
+	     irq++, desc = irq_to_desc(irq))				\
+		if (desc)
+
+
 # define for_each_irq_desc_reverse(irq, desc)				\
 	for (irq = nr_irqs - 1, desc = irq_to_desc(irq); irq >= 0;	\
-	     irq--, desc = irq_to_desc(irq))
+	     irq--, desc = irq_to_desc(irq))				\
+		if (desc)
 
 #endif /* CONFIG_GENERIC_HARDIRQS */