rcu: Delete unused rcu_node "wakemask" field

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index c896b50..8e75609 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -134,9 +134,6 @@
 				/*  elements that need to drain to allow the */
 				/*  current expedited grace period to */
 				/*  complete (only for TREE_PREEMPT_RCU). */
-	atomic_t wakemask;	/* CPUs whose kthread needs to be awakened. */
-				/*  Since this has meaning only for leaf */
-				/*  rcu_node structures, 32 bits suffices. */
 	unsigned long qsmaskinit;
 				/* Per-GP initial value for qsmask & expmask. */
 	unsigned long grpmask;	/* Mask to apply to parent qsmask. */