Staging: wlan-ng: wiphy_free() is not called in case wiphy_register() fails

This patch covers wiphy_register() failures in wlan_create_wiphy()
from cfg80211.c by calling wiphy_free() for the correspondent
struct wiphy allocated structure.

Signed-off-by: Claudiu Beznea <claudiu.beznea@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>