bsd-family-tree: Add missing releases

- NetBSD 6.0.4
- DragonFly 3.6.2
Make sure bf_next is NULL'ed out when we're completing up an aggregate
frame through the cleanup path.

Whilst here, fix the indenting for something I messed up.

Tested:

* AR5416, STA mode
* Modify the debugging output from pause/resume to note the TID and STA
  MAC
* Now that the paused < 0 bugs have been identified, make the DPRINTF()
  a device_printf() again.  Anything else that shows up here needs to be
  fixed immediately.

Tested:

* AR5416, STA mode

MFC after:	7 days