srcu: Disable interrupts directly in srcu_gp_end()

Interrupts are enabled in srcu_gp_end(), so this commit switches from
spin_lock_irqsave_rcu_node() and spin_unlock_irqrestore_rcu_node()
to spin_lock_irq_rcu_node() and spin_unlock_irq_rcu_node().

Link: https://lore.kernel.org/all/febb13ab-a4bb-48b4-8e97-7e9f7749e6da@moroto.mountain/Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

kernel/rcu/srcutree.c

@@ -845,7 +845,6 @@ static void srcu_gp_end(struct srcu_struct *ssp)
 	bool cbs;
 	bool last_lvl;
 	int cpu;
-	unsigned long flags;
 	unsigned long gpseq;
 	int idx;
 	unsigned long mask;
@@ -907,12 +906,12 @@ static void srcu_gp_end(struct srcu_struct *ssp)
 	if (!(gpseq & counter_wrap_check))
 		for_each_possible_cpu(cpu) {
 			sdp = per_cpu_ptr(ssp->sda, cpu);
-			spin_lock_irqsave_rcu_node(sdp, flags);
+			spin_lock_irq_rcu_node(sdp);
 			if (ULONG_CMP_GE(gpseq, sdp->srcu_gp_seq_needed + 100))
 				sdp->srcu_gp_seq_needed = gpseq;
 			if (ULONG_CMP_GE(gpseq, sdp->srcu_gp_seq_needed_exp + 100))
 				sdp->srcu_gp_seq_needed_exp = gpseq;
-			spin_unlock_irqrestore_rcu_node(sdp, flags);
+			spin_unlock_irq_rcu_node(sdp);
 		}
 
 	/* Callback initiation done, allow grace periods after next. */