staging: r8188eu: replace one GetAddr3Ptr call

Define a struct ieee80211_mgmt for the message that we process in
OnDeAuth. Use this struct to read the bssid.

This patch removes one GetAddr3Ptr call, getting us a tiny step closer to
removing GetAddr3Ptr.
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/20221015152440.232281-2-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_mlme_ext.c

@@ -1457,6 +1457,7 @@ unsigned int OnAssocRsp(struct adapter *padapter, struct recv_frame *precv_frame
 
 unsigned int OnDeAuth(struct adapter *padapter, struct recv_frame *precv_frame)
 {
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)precv_frame->rx_data;
 	unsigned short	reason;
 	struct mlme_priv *pmlmepriv = &padapter->mlmepriv;
 	struct mlme_ext_priv	*pmlmeext = &padapter->mlmeextpriv;
@@ -1464,8 +1465,7 @@ unsigned int OnDeAuth(struct adapter *padapter, struct recv_frame *precv_frame)
 	u8 *pframe = precv_frame->rx_data;
 	struct wifidirect_info *pwdinfo = &padapter->wdinfo;
 
-	/* check A3 */
-	if (!(!memcmp(GetAddr3Ptr(pframe), get_my_bssid(&pmlmeinfo->network), ETH_ALEN)))
+	if (memcmp(mgmt->bssid, get_my_bssid(&pmlmeinfo->network), ETH_ALEN))
 		return _SUCCESS;
 
 	if (pwdinfo->rx_invitereq_info.scan_op_ch_only) {