LinuxKPI: 802.11: update the ni/lsta reference cycle

[bz]

Summary

Update the ni/lsta reference cycle, add extra checks and assertions.
This is to accomodate problems we were seeing based on net80211
behaviour (join1() and (*iv_update_bss)() as well as state changes for
new iv_bss nodes during an active session).
This should hopefully help to stabilise behaviour until the underlying
problems gets properly addressed (for this and all other device drivers).

XXX-NOTE: this contains last minutes cleanup and one function chnage not
tested yet.

MFC after: 3 days

Test Plan

Depends on D43725 being applied first.

[cc]

My initial test on the three patches of D43389, D43725, D43753 looks to be good. No more panics. And I need to figure out some issues in my testbed, so I give the approval first as I don't want my test to delay the schedule.