cfg80211: fix sending WoWLAN TCP wakeup settings

commit e248ad30 upstream.

The code sending the current WoWLAN TCP wakeup settings in
nl80211_send_wowlan_tcp() is not closing the nested attribute,
thus causing the parser to get confused on the receiver side
in userspace (iw). Fix this.

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