genirq: fix off by one and coding style

Fix off-by-one in for_each_irq_desc_reverse().

Impact is near zero in practice, because nothing substantial wants to
iterate down to IRQ#0 - but fix it nevertheless.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/irq.c

@@ -36,7 +36,7 @@ void ack_bad_irq(unsigned int irq)
 }
 
 #ifdef CONFIG_X86_32
-# define irq_stats(x)		(&per_cpu(irq_stat,x))
+# define irq_stats(x)		(&per_cpu(irq_stat, x))
 #else
 # define irq_stats(x)		cpu_pda(x)
 #endif
@@ -113,7 +113,7 @@ int show_interrupts(struct seq_file *p, void *v)
 	if (i == 0) {
 		seq_printf(p, "           ");
 		for_each_online_cpu(j)
-			seq_printf(p, "CPU%-8d",j);
+			seq_printf(p, "CPU%-8d", j);
 		seq_putc(p, '\n');
 	}
 

include/linux/irqnr.h

@@ -13,9 +13,9 @@ extern int nr_irqs;
 # define for_each_irq_desc(irq, desc)		\
 	for (irq = 0, desc = irq_desc; irq < nr_irqs; irq++, desc++)
 
-# define for_each_irq_desc_reverse(irq, desc)			\
-	for (irq = nr_irqs -1, desc = irq_desc + (nr_irqs -1 );	\
-	     irq > 0; irq--, desc--)
+# define for_each_irq_desc_reverse(irq, desc)				\
+	for (irq = nr_irqs - 1, desc = irq_desc + (nr_irqs - 1);	\
+	     irq >= 0; irq--, desc--)
 #endif
 
 #define for_each_irq_nr(irq)			\