mac80211: fix function pointer check

This makes "iw wlan0 dump survey" work again with
mac80211-based drivers that support it, e.g. ath5k.

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 file changed