ray_cs: use remove_proc_subtree to simplify procfs code

Use remove_proc_subtree to remove the whole subtree

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/ray_cs.c b/drivers/net/wireless/ray_cs.c
index d561659..ee4d810 100644
--- a/drivers/net/wireless/ray_cs.c
+++ b/drivers/net/wireless/ray_cs.c
@@ -2820,11 +2820,7 @@ static void __exit exit_ray_cs(void)
 	pr_debug("ray_cs: cleanup_module\n");
 
 #ifdef CONFIG_PROC_FS
-	remove_proc_entry("driver/ray_cs/ray_cs", NULL);
-	remove_proc_entry("driver/ray_cs/essid", NULL);
-	remove_proc_entry("driver/ray_cs/net_type", NULL);
-	remove_proc_entry("driver/ray_cs/translate", NULL);
-	remove_proc_entry("driver/ray_cs", NULL);
+	remove_proc_subtree("driver/ray_cs", NULL);
 #endif
 
 	pcmcia_unregister_driver(&ray_driver);