srcu: Abstract function name

This commit moves to __func__ for function names in the name of better
resilience to change.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcu/srcutree.c

@@ -386,7 +386,7 @@ void cleanup_srcu_struct(struct srcu_struct *sp)
 		flush_delayed_work(&per_cpu_ptr(sp->sda, cpu)->work);
 	if (WARN_ON(rcu_seq_state(READ_ONCE(sp->srcu_gp_seq)) != SRCU_STATE_IDLE) ||
 	    WARN_ON(srcu_readers_active(sp))) {
-		pr_info("cleanup_srcu_struct: Active srcu_struct %p state: %d\n", sp, rcu_seq_state(READ_ONCE(sp->srcu_gp_seq)));
+		pr_info("%s: Active srcu_struct %p state: %d\n", __func__, sp, rcu_seq_state(READ_ONCE(sp->srcu_gp_seq)));
 		return; /* Caller forgot to stop doing call_srcu()? */
 	}
 	free_percpu(sp->sda);