rcu: Inline trivial wrapper function rcu_start_gp_per_cpu()

Given the changes that introduce note_gp_change(), rcu_start_gp_per_cpu()
is now a trivial wrapper function with only one caller.  This commit
therefore inlines it into its sole call site.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

kernel/rcutree.c

@@ -1307,18 +1307,6 @@ static void note_gp_changes(struct rcu_state *rsp, struct rcu_data *rdp)
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 }
 
-/*
- * Do per-CPU grace-period initialization for running CPU.  The caller
- * must hold the lock of the leaf rcu_node structure corresponding to
- * this CPU.
- */
-static void
-rcu_start_gp_per_cpu(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
-{
-	/* Set state so that this CPU will detect the next quiescent state. */
-	__note_gp_changes(rsp, rnp, rdp);
-}
-
 /*
  * Initialize a new grace period.
  */
@@ -1367,7 +1355,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
 		WARN_ON_ONCE(rnp->completed != rsp->completed);
 		ACCESS_ONCE(rnp->completed) = rsp->completed;
 		if (rnp == rdp->mynode)
-			rcu_start_gp_per_cpu(rsp, rnp, rdp);
+			__note_gp_changes(rsp, rnp, rdp);
 		rcu_preempt_boost_start_gp(rnp);
 		trace_rcu_grace_period_init(rsp->name, rnp->gpnum,
 					    rnp->level, rnp->grplo,