[PATCH] skb used after passing to netif_rx in net/ieee80211/ieee80211_rx.c

this patch fixes coverity id #913. ieee80211_monitor_rx() passes the skb
to netif_rx() and we should not reference it any longer.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>