wifi: mac80211: fix warning on disconnect during failed ML reconf

wifi: mac80211: fix warning on disconnect during failed ML reconf

If multi-link reconfiguration fails, we can disconnect with a local link
already allocated but the BSS entry not assigned yet, which leads to a
warning in cfg80211. Add a check to avoid the warning.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250308225541.699bd9cbabe5.I599d5ff69092a65e916e2acd25137ae9df8debe8@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>