Fix 'Driver using old /proc/net/wireless support, please fix driver !' message.

Wireless extensions moved the get_wireless_stats handler from being
in net_device into wireless_handler.

Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>