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

drivers/net/wireless/intel/iwlwifi/mvm/sta.c

@@ -2070,13 +2070,6 @@ bool iwl_mvm_sta_del(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 		cancel_delayed_work(&mvm->tdls_cs.dwork);
 	}
 
-	/*
-	 * Make sure that the tx response code sees the station as -EBUSY and
-	 * calls the drain worker.
-	 */
-	spin_lock_bh(&mvm_sta->lock);
-	spin_unlock_bh(&mvm_sta->lock);
-
 	return false;
 }