add docstring

src/status_im/hardwallet/core.cljs

@@ -1499,6 +1499,12 @@
   {:db (assoc-in db [:hardwallet :pairings] pairings)})
 
 (fx/defn on-pair-success
+  "When pairing to device completed, we need to persist pairing data to
+  local storage. That's needed for to ensure that during keycard setup
+  keycard won't run out of pairings slots, ie. we don't pair same
+  card to same device more than one time. Also, this allows user to proceed
+  with setup skiping pairing step if pairing was already done during previous
+  unfinished setup."
   [{:keys [db] :as cofx} pairing]
   (let [setup-step (get-in db [:hardwallet :setup-step])
         flow (get-in db [:hardwallet :flow])
@@ -1507,7 +1513,6 @@
         paired-on (utils.datetime/timestamp)
         pairings (assoc (get-in db [:hardwallet :pairings]) instance-uid {:pairing   pairing
                                                                           :paired-on paired-on})
-        instance-uid (get-in db [:hardwallet :application-info :instance-uid])
         next-step (if (= setup-step :pair)
                     :begin
                     :card-ready)]