staging: vt6656: Fix calling conditions of vnt_set_bss_mode

vnt_set_bss_mode needs to be called on all changes to BSS_CHANGED_BASIC_RATES,
BSS_CHANGED_ERP_PREAMBLE and BSS_CHANGED_ERP_SLOT

Remove all other calls and vnt_update_ifs which is called in vnt_set_bss_mode.

Fixes an issue that preamble mode is not being updated correctly.

Fixes: c12603576e ("staging: vt6656: Only call vnt_set_bss_mode on basic rates change.")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/44110801-6234-50d8-c583-9388f04b486c@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/main_usb.c

@@ -625,8 +625,6 @@ static int vnt_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 
 	priv->op_mode = vif->type;
 
-	vnt_set_bss_mode(priv);
-
 	/* LED blink on TX */
 	vnt_mac_set_led(priv, LEDSTS_STS, LEDSTS_INTER);
 
@@ -713,7 +711,6 @@ static void vnt_bss_info_changed(struct ieee80211_hw *hw,
 		priv->basic_rates = conf->basic_rates;
 
 		vnt_update_top_rates(priv);
-		vnt_set_bss_mode(priv);
 
 		dev_dbg(&priv->usb->dev, "basic rates %x\n", conf->basic_rates);
 	}
@@ -742,11 +739,14 @@ static void vnt_bss_info_changed(struct ieee80211_hw *hw,
 			priv->short_slot_time = false;
 
 		vnt_set_short_slot_time(priv);
-		vnt_update_ifs(priv);
 		vnt_set_vga_gain_offset(priv, priv->bb_vga[0]);
 		vnt_update_pre_ed_threshold(priv, false);
 	}
 
+	if (changed & (BSS_CHANGED_BASIC_RATES | BSS_CHANGED_ERP_PREAMBLE |
+		       BSS_CHANGED_ERP_SLOT))
+		vnt_set_bss_mode(priv);
+
 	if (changed & BSS_CHANGED_TXPOWER)
 		vnt_rf_setpower(priv, priv->current_rate,
 				conf->chandef.chan->hw_value);