lnwallet+input: fix a few typoes

lnwire/update_add_htlc.go

@@ -15,7 +15,7 @@ const OnionPacketSize = 1366
 // HTLC to his remote commitment transaction. In addition to information
 // detailing the value, the ID, expiry, and the onion blob is also included
 // which allows Bob to derive the next hop in the route. The HTLC added by this
-// message is to be added to the remote node's "pending" HTLC's.  A subsequent
+// message is to be added to the remote node's "pending" HTLCs.  A subsequent
 // CommitSig message will move the pending HTLC to the newly created commitment
 // transaction, marking them as "staged".
 type UpdateAddHTLC struct {