wifi: iwlwifi: mvm: remove useless code

Setting the station to -EBUSY was originally done under
this lock, and the comment still refers to it. But this
no longer happens because that was removed when DQA was
removed. Remove the leftover code as well.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230524203151.30048b1cd0fd.Ie2c2ff6fd7c6e3ebf5b736de350dc15515970792@changeid


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