fix:
  CC      kernel/rcuclassic.o
kernel/rcuclassic.c: In function '__rcu_process_callbacks':
kernel/rcuclassic.c:561: error: 'flags' undeclared (first use in this function)
kernel/rcuclassic.c:561: error: (Each undeclared identifier is reported only once
kernel/rcuclassic.c:561: error: for each function it appears in.)
Declare missing variable flags.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
                local_irq_enable();
 
                if (rcu_batch_after(rdp->batch, rcp->pending)) {
+                       unsigned long flags;
+
                        /* and start it/schedule start if it's a new batch */
                        spin_lock_irqsave(&rcp->lock, flags);
                        if (rcu_batch_after(rdp->batch, rcp->pending)) {