staging/wlan-ng: remove function declaration

Removed useless function prototype: static function p80211netdev_rx_bh()
is defined before being used.
Signed-off-by: Denis Pithon <denis.pithon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/p80211netdev.c

@@ -90,9 +90,6 @@
 
 #include "cfg80211.c"
 
-/* Support functions */
-static void p80211netdev_rx_bh(unsigned long arg);
-
 /* netdevice method functions */
 static int p80211knetdev_init(netdevice_t *netdev);
 static struct net_device_stats *p80211knetdev_get_stats(netdevice_t *netdev);