PM: EM: use kfree_rcu() to simplify the code

The callback function of call_rcu() just calls kfree(), so use
kfree_rcu() instead of call_rcu() + callback function.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20250218082021.2766-1-lirongqing@baidu.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: lrq-max

kernel/power/energy_model.c

@@ -161,22 +161,14 @@ static void em_debug_create_pd(struct device *dev) {}
 static void em_debug_remove_pd(struct device *dev) {}
 #endif
 
-static void em_destroy_table_rcu(struct rcu_head *rp)
-{
-	struct em_perf_table __rcu *table;
-
-	table = container_of(rp, struct em_perf_table, rcu);
-	kfree(table);
-}
-
 static void em_release_table_kref(struct kref *kref)
 {
 	struct em_perf_table __rcu *table;
 
 	/* It was the last owner of this table so we can free */
 	table = container_of(kref, struct em_perf_table, kref);
 
-	call_rcu(&table->rcu, em_destroy_table_rcu);
+	kfree_rcu(table, rcu);
 }
 
 /**