Jouni reported that with mac80211_hwsim, multicast TX was causing
crashes due to invalid vif->cab_queue assignment. It turns out that
this is caused by change_interface() getting invoked and not having
the vif->type/vif->p2p assigned correctly before calling the queue
check (ieee80211_check_queues). Fix this by passing the 'external'
interface type to the function and adjusting it accordingly.

While at it, also fix the error path in change_interface, it wasn't
correctly resetting to the external type but using the internal one
instead.

Fortunately this affects on hwsim because all other drivers set the
vif->type/vif->p2p variables when changing iftype. This shouldn't
be needed, but almost all implementations actually do it for their
own internal handling.
Reported-by: NJouni Malinen <j@w1.fi>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>