rtlwifi: drop unused ppsc->last_wakeup_time

The calculation of ppsc->last_wakeup_time is not y2038-safe, but
the variable is not used at all, so we can simply drop it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/rtl8821ae/hw.c

@@ -1364,7 +1364,6 @@ static void _rtl8821ae_get_wakeup_reason(struct ieee80211_hw *hw)
 	struct rtl_hal *rtlhal = rtl_hal(rtl_priv(hw));
 	struct rtl_ps_ctl *ppsc = rtl_psc(rtlpriv);
 	u8 fw_reason = 0;
-	struct timeval ts;
 
 	fw_reason = rtl_read_byte(rtlpriv, REG_MCUTST_WOWLAN);
 
@@ -1378,15 +1377,11 @@ static void _rtl8821ae_get_wakeup_reason(struct ieee80211_hw *hw)
 	switch (fw_reason) {
 	case FW_WOW_V2_PTK_UPDATE_EVENT:
 		ppsc->wakeup_reason = WOL_REASON_PTK_UPDATE;
-		do_gettimeofday(&ts);
-		ppsc->last_wakeup_time = ts.tv_sec*1000 + ts.tv_usec/1000;
 		RT_TRACE(rtlpriv, COMP_POWER, DBG_DMESG,
 			 "It's a WOL PTK Key update event!\n");
 		break;
 	case FW_WOW_V2_GTK_UPDATE_EVENT:
 		ppsc->wakeup_reason = WOL_REASON_GTK_UPDATE;
-		do_gettimeofday(&ts);
-		ppsc->last_wakeup_time = ts.tv_sec*1000 + ts.tv_usec/1000;
 		RT_TRACE(rtlpriv, COMP_POWER, DBG_DMESG,
 			 "It's a WOL GTK Key update event!\n");
 		break;

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

@@ -1954,8 +1954,6 @@ struct rtl_ps_ctl {
 	u8 gtk_offload_enable;
 	/* Used for WOL, indicates the reason for waking event.*/
 	u32 wakeup_reason;
-	/* Record the last waking time for comparison with setting key. */
-	u64 last_wakeup_time;
 };
 
 struct rtl_stats {