pasemi_mac: A couple of minor bugfixes.

Bugfixes:

* Move the wake_queue logic from tx_intr to clean_tx
* Always do wake_queue even if queue wasn't full before clean since
  it's safe to do
* Fix polarity in checks in pasemi_mac_close

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>