softirq: allocate less vectors

We don't need whole 32 of them, only NR_SOFTIRQS.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 58ff4e7..54b3623 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -252,6 +252,8 @@
 	HRTIMER_SOFTIRQ,
 #endif
 	RCU_SOFTIRQ, 	/* Preferable RCU should always be the last softirq */
+
+	NR_SOFTIRQS
 };
 
 /* softirq mask and active fields moved to irq_cpustat_t in