Merge branch 'collection-of-dsa-bug-fixes'

Vladimir Oltean says:

====================
Collection of DSA bug fixes

Prompted by Russell King's 3 DSA bug reports from Friday (linked in
their respective patches: 1, 2 and 3), I am providing fixes to those, as
well as flushing the queue with 2 other bug fixes I had.

1: fix NULL pointer dereference during mv88e6xxx driver unbind, on old
   switch models which lack PVT and/or STU. Seen on the ZII dev board
   rev B.
2: fix failure to delete bridge port VLANs on old mv88e6xxx chips which
   lack STU. Seen on the same board.
3: fix WARN_ON() and resource leak in DSA core on driver unbind. Seen on
   the same board but is a much more widespread issue.
4: fix use-after-free during probing of DSA trees with >= 3 switches,
   if -EPROBE_DEFER exists. In principle issue also exists for the ZII
   board, I reproduced on Turris MOX.
5: fix incorrect use of refcount API in DSA core for those switches
   which use tag_8021q (felix, sja1105, vsc73xx). Returning an error
   when attempting to delete a tag_8021q VLAN prints a WARN_ON(), which
   is harmless but might be problematic with CONFIG_PANIC_ON_OOPS.
====================

Link: https://patch.msgid.link/20250414212708.2948164-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>