staging: wlan-ng: add missing byte order conversion

Conversion macros le16_to_cpu was removed and that caused new sparse warning

sparse output:
drivers/staging/wlan-ng/p80211netdev.c:241:44: warning: incorrect type in argument 2 (different base types)
drivers/staging/wlan-ng/p80211netdev.c:241:44:    expected unsigned short [unsigned] [usertype] fc
drivers/staging/wlan-ng/p80211netdev.c:241:44:    got restricted __le16 [usertype] fc

Fixes: 7ad82572 ("staging:wlan-ng:Fix sparse warning")
Signed-off-by: Igor Pylypiv <igor.pylypiv@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/p80211netdev.c

@@ -237,7 +237,7 @@ static int p80211_convert_to_ether(struct wlandevice *wlandev,
 	struct p80211_hdr_a3 *hdr;
 
 	hdr = (struct p80211_hdr_a3 *)skb->data;
-	if (p80211_rx_typedrop(wlandev, hdr->fc))
+	if (p80211_rx_typedrop(wlandev, le16_to_cpu(hdr->fc)))
 		return CONV_TO_ETHER_SKIPPED;
 
 	/* perform mcast filtering: allow my local address through but reject