rtlwifi: use to_delayed_work()

Use to_delayed_work() instead of open-coding it.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
[Update commit message]
Signed-off-by: NJulian Calaby <julian.calaby@gmail.com>
Acked-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/wifi.h

@@ -2870,7 +2870,7 @@ value to host byte ordering.*/
 	(ppsc->cur_ps_level |= _ps_flg)
 
 #define container_of_dwork_rtl(x, y, z) \
-	container_of(container_of(x, struct delayed_work, work), y, z)
+	container_of(to_delayed_work(x), y, z)
 
 #define FILL_OCTET_STRING(_os, _octet, _len)	\
 		(_os).octet = (u8 *)(_octet);		\