x86: use nr_irqs

also add first_free_entry and pin_map_size, which were NR_IRQS derived
constants.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/irqinit_32.c b/arch/x86/kernel/irqinit_32.c
index 9200a1e..65c1c95 100644
--- a/arch/x86/kernel/irqinit_32.c
+++ b/arch/x86/kernel/irqinit_32.c
@@ -100,7 +100,7 @@
 	 */
 	for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
 		int vector = FIRST_EXTERNAL_VECTOR + i;
-		if (i >= NR_IRQS)
+		if (i >= nr_irqs)
 			break;
 		/* SYSCALL_VECTOR was reserved in trap_init. */
 		if (!test_bit(vector, used_vectors))