wifi: iwlwifi: mld: cancel mlo_scan_start_wk

wifi: iwlwifi: mld: cancel mlo_scan_start_wk

mlo_scan_start_wk is not canceled on disconnection. In fact, it is not
canceled anywhere except in the restart cleanup, where we don't really
have to.

This can cause an init-after-queue issue: if, for example, the work was
queued and then drv_change_interface got executed.

This can also cause use-after-free: if the work is executed after the
vif is freed.

Fixes: 9748ad82a9d9 ("wifi: iwlwifi: defer MLO scan after link activation")
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20260129212650.a36482a60719.I5bf64a108ca39dacb5ca0dcd8b7258a3ce8db74c@changeid