staging: r8188eu: exit for deauth from unknown station

If we receive a deauth message from an unknown station, we can drop this
message and exit immediately. Reorder the code to make this clearer, don't
wrap everything in an if statement.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Acked-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/20221015152440.232281-7-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_mlme_ext.c

@@ -1477,21 +1477,21 @@ unsigned int OnDeAuth(struct adapter *padapter, struct recv_frame *precv_frame)
 	if (check_fwstate(pmlmepriv, WIFI_AP_STATE)) {
 		struct sta_info *psta;
 		struct sta_priv *pstapriv = &padapter->stapriv;
+		u8 updated = 0;
 
 		psta = rtw_get_stainfo(pstapriv, mgmt->sa);
-		if (psta) {
-			u8 updated = 0;
-
-			spin_lock_bh(&pstapriv->asoc_list_lock);
-			if (!list_empty(&psta->asoc_list)) {
-				list_del_init(&psta->asoc_list);
-				pstapriv->asoc_list_cnt--;
-				updated = ap_free_sta(padapter, psta, false, reason);
-			}
-			spin_unlock_bh(&pstapriv->asoc_list_lock);
+		if (!psta)
+			return _SUCCESS;
 
-			associated_clients_update(padapter, updated);
+		spin_lock_bh(&pstapriv->asoc_list_lock);
+		if (!list_empty(&psta->asoc_list)) {
+			list_del_init(&psta->asoc_list);
+			pstapriv->asoc_list_cnt--;
+			updated = ap_free_sta(padapter, psta, false, reason);
 		}
+		spin_unlock_bh(&pstapriv->asoc_list_lock);
+
+		associated_clients_update(padapter, updated);
 
 		return _SUCCESS;
 	} else {