wifi: iwlwifi: mvm: correctly use link in iwl_mvm_sta_del()

This function can be invoked for both MLO and non-MLO, so
it must deal with multi-link correctly. Notable, on auth
timeout, we'd otherwise get a warning due to the erroneous
deflink usage in MLO cases.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230329100040.b85f6052d51a.Iedfef4b4c4f3ca557aebc0093fdc3f5cfb49b507@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>