rtlwifi: rtl8192ee: Fix potential race condition

Flag rfchange_inprogress in struct rtl_ps_ctl is protected by a spinlock
in most routines but not in rtl92ee_dm_watchdog(), which could
lead to a race condition. The necessary locking to prevent this condition
is added.

Reported-by: Pavel Andrianov <andrianov@ispras.ru>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Pavel Andrianov <andrianov@ispras.ru>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/rtl8192ee/dm.c

@@ -1219,6 +1219,7 @@ void rtl92ee_dm_watchdog(struct ieee80211_hw *hw)
 	if (ppsc->p2p_ps_info.p2p_ps_mode)
 		fw_ps_awake = false;
 
+	spin_lock(&rtlpriv->locks.rf_ps_lock);
 	if ((ppsc->rfpwr_state == ERFON) &&
 	    ((!fw_current_inpsmode) && fw_ps_awake) &&
 	    (!ppsc->rfchange_inprogress)) {
@@ -1233,4 +1234,5 @@ void rtl92ee_dm_watchdog(struct ieee80211_hw *hw)
 		rtl92ee_dm_dynamic_atc_switch(hw);
 		rtl92ee_dm_dynamic_primary_cca_ckeck(hw);
 	}
+	spin_unlock(&rtlpriv->locks.rf_ps_lock);
 }