ARM: fix /proc/interrupts formatting

As per x86, align the initial column according to how many IRQs we
have.  Also, provide an english explaination for the 'LOC:' and
'IPI:' lines.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index ea29721..4e7a7d2 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -57,11 +57,15 @@
 	struct irq_desc *desc;
 	struct irqaction * action;
 	unsigned long flags;
+	int prec, n;
+
+	for (prec = 3, n = 1000; prec < 10 && n <= nr_irqs; prec++)
+		n *= 10;
 
 	if (i == 0) {
 		char cpuname[12];
 
-		seq_printf(p, "    ");
+		seq_printf(p, "%*s ", prec, "");
 		for_each_present_cpu(cpu) {
 			sprintf(cpuname, "CPU%d", cpu);
 			seq_printf(p, " %10s", cpuname);
@@ -76,7 +80,7 @@
 		if (!action)
 			goto unlock;
 
-		seq_printf(p, "%3d: ", i);
+		seq_printf(p, "%*d: ", prec, i);
 		for_each_present_cpu(cpu)
 			seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu));
 		seq_printf(p, " %10s", desc->chip->name ? : "-");
@@ -89,15 +93,15 @@
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
 	} else if (i == nr_irqs) {
 #ifdef CONFIG_FIQ
-		show_fiq_list(p, v);
+		show_fiq_list(p, prec);
 #endif
 #ifdef CONFIG_SMP
-		show_ipi_list(p);
+		show_ipi_list(p, prec);
 #endif
 #ifdef CONFIG_LOCAL_TIMERS
-		show_local_irqs(p);
+		show_local_irqs(p, prec);
 #endif
-		seq_printf(p, "Err: %10lu\n", irq_err_count);
+		seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
 	}
 	return 0;
 }