wifi: mac80211: take lock before setting vif links

ieee80211_vif_set_links requires the sdata->local->mtx lock to be held.
Add the appropriate locking around the calls in both the link add and
remove handlers.

This causes a warning when e.g. ieee80211_link_release_channel is called
via ieee80211_link_stop from ieee80211_vif_update_links.

Fixes: 0d8c4a3c

 ("wifi: mac80211: implement add/del interface link callbacks")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230608163202.fa0c6597fdad.I83dd70359f6cda30f86df8418d929c2064cf4995@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>