* iwm_xmit_queue_drain() calls ieee80211_free_node(), removing a possible
memory leak, compared to using just mbufq_drain().
* Remove duplicate mbufq_drain() from iwm_mvm_rm_sta(), this should be
handled in the caller.
Obtained from: dragonflybsd.git 339d45fda40072e0aca5ece639173204716f11fe