mac80211: fix bugs in queue handling functions

Commit 55c308c1315bc7267dbb88011c208fd743cdce31
("mac80211: QoS related cleanups") introduced another bug,
the queue handling functions that operate on all queues now
only operated on the first queues, not the A-MPDU queues as
expected. This patch fixes this.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>