cfg80211: fix wiphy_register error path

commit 03cd7e4e upstream.

If rfkill_register() fails in wiphy_register() the struct device
is unregistered but everything else isn't (regulatory, debugfs)
and we even leave the wiphy instance on all internal lists even
though it will likely be freed soon, which is clearly a problem.
Fix this by cleaning up properly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>