wifi: iwlwifi: mvm: fix initialization of a return value

In iwl_mvm_mld_update_sta(), if the flow doesn't enter
for_each_sta_active_link(), the default value is returned.
Set this default to -EINVAL instead of 0 to better reflect
this.
Signed-off-by: Mukesh Sisodiya <mukesh.sisodiya@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230514120631.98b7e3aacf0b.I2fc274dd7e374ef7fac8e26d71c9cd73323da665@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

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

@@ -728,7 +728,7 @@ int iwl_mvm_mld_update_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 	struct iwl_mvm_sta *mvm_sta = iwl_mvm_sta_from_mac80211(sta);
 	struct ieee80211_link_sta *link_sta;
 	unsigned int link_id;
-	int ret = 0;
+	int ret = -EINVAL;
 
 	lockdep_assert_held(&mvm->mutex);