mac80211: Remove check for offchannel state when waking netdev queues

6c17b77b ensures that a device's
mac80211 queues will remain stopped while offchannel. Since the
vif can no longer be offchannel when the queues wake it's not
necessary to check for this before waking its netdev queues.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>