wifi: iwlwifi: mvm: fix an error code in iwl_mvm_mld_add_sta()

This error path should return -EINVAL instead of success.

Fixes: 57974a55 ("wifi: iwlwifi: mvm: refactor iwl_mvm_mac_sta_state_common()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/75e4ea09-db58-462f-bd4e-5ad4e5e5dcb5@moroto.mountainSigned-off-by: Johannes Berg <johannes.berg@intel.com>

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

@@ -707,8 +707,10 @@ int iwl_mvm_mld_add_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 			rcu_dereference_protected(mvm_sta->link[link_id],
 						  lockdep_is_held(&mvm->mutex));
 
-		if (WARN_ON(!link_conf || !mvm_link_sta))
+		if (WARN_ON(!link_conf || !mvm_link_sta)) {
+			ret = -EINVAL;
 			goto err;
+		}
 
 		ret = iwl_mvm_mld_cfg_sta(mvm, sta, vif, link_sta, link_conf,
 					  mvm_link_sta);