staging: r8712u: Fix case where ethtype was never obtained and always be checked against 0

commit f764cd68 upstream.

Zero-initializing ether_type masked that the ether type would never be
obtained for 8021x packets and the comparison against eapol_type
would always fail.
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/rtl871x_recv.c

@@ -253,7 +253,7 @@ union recv_frame *r8712_portctrl(struct _adapter *adapter,
 	struct sta_info *psta;
 	struct	sta_priv *pstapriv;
 	union recv_frame *prtnframe;
-	u16 ether_type = 0;
+	u16 ether_type;
 
 	pstapriv = &adapter->stapriv;
 	ptr = get_recvframe_data(precv_frame);
@@ -262,15 +262,14 @@ union recv_frame *r8712_portctrl(struct _adapter *adapter,
 	psta = r8712_get_stainfo(pstapriv, psta_addr);
 	auth_alg = adapter->securitypriv.AuthAlgrthm;
 	if (auth_alg == 2) {
+		/* get ether_type */
+		ptr = ptr + pfhdr->attrib.hdrlen + LLC_HEADER_SIZE;
+		memcpy(&ether_type, ptr, 2);
+		ether_type = ntohs((unsigned short)ether_type);
+
 		if ((psta != NULL) && (psta->ieee8021x_blocked)) {
 			/* blocked
 			 * only accept EAPOL frame */
-			prtnframe = precv_frame;
-			/*get ether_type */
-			ptr = ptr + pfhdr->attrib.hdrlen +
-			      pfhdr->attrib.iv_len + LLC_HEADER_SIZE;
-			memcpy(&ether_type, ptr, 2);
-			ether_type = ntohs((unsigned short)ether_type);
 			if (ether_type == 0x888e)
 				prtnframe = precv_frame;
 			else {