mutexes and replacing the obsolete if_watchdog interface. The ndis_ticktask
function calls into ieee80211_new_state under one condition with NDIS_LOCK
held. The ieee80211_new_state would call into ndis_start in some cases too,
resulting in the occasional case where ndis_start acquires NDIS_LOCK from
inside the NDIS_LOCK held by ndis_ticktask.
Obtained from: Paul B. Mahol <onemda@gmail.com>
MFC after: 1 week