iwlegacy: always monitor for stuck queues

iwlegacy: always monitor for stuck queues

commit c2ca7d92ed4bbd779516beb6eb226e19f7f7ab0f upstream.

This is iwlegacy version of:

commit 342bbf3fee2fa9a18147e74b2e3c4229a4564912
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Sun Mar 4 08:50:46 2012 -0800

    iwlwifi: always monitor for stuck queues

    If we only monitor while associated, the following
    can happen:
     - we're associated, and the queue stuck check
       runs, setting the queue "touch" time to X
     - we disassociate, stopping the monitoring,
       which leaves the time set to X
     - almost 2s later, we associate, and enqueue
       a frame
     - before the frame is transmitted, we monitor
       for stuck queues, and find the time set to
       X, although it is now later than X + 2000ms,
       so we decide that the queue is stuck and
       erroneously restart the device

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: adjust filename, function and variable names]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>