mac80211: fix a few RCU issues

commit a3836e02 upstream.

A few configuration functions correctly do
rcu_read_lock() but don't correctly reference
some pointers protected by RCU. Fix that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>