staging: rtl8723au: process_80211d(): Fix order of advancing array pos

Fix smatch warning from advancing array index before reading out the
value of the array.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723au/core/rtw_mlme_ext.c

@@ -4867,9 +4867,9 @@ static void process_80211d(struct rtw_adapter *padapter,
 		if (!ie || ie[1] < IEEE80211_COUNTRY_IE_MIN_LEN)
 			return;
 
-		ie += 2;
-		p = ie;
+		p = ie + 2;
 		ie += ie[1];
+		ie += 2;
 
 		memcpy(country, p, 3);
 		country[3] = '\0';