mac80211: ignore HT primary channel while connected

While we're connected, the AP shouldn't change the primary channel
in the HT information. We checked this, and dropped the connection
if it did change it.

Unfortunately, this is causing problems on some APs, e.g. on the
Netgear WRT610NL: the beacons seem to always contain a bad channel
and if we made a connection using a probe response (correct data)
we drop the connection immediately and can basically not connect
properly at all.

Work around this by ignoring the HT primary channel information in
beacons if we're already connected.

Also print out more verbose messages in the other situations to
help diagnose similar bugs quicker in the future.

Cc: stable@vger.kernel.org [3.10]
Acked-by: Andy Isaacson <adi@hexapodia.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>