Document record mixing mail swap

src/party_menu.c

@@ -1726,7 +1726,7 @@ static void GiveItemToMon(struct Pokemon *mon, u16 item)
 
     if (ItemIsMail(item) == TRUE)
     {
-        if (GiveMailToMon(mon, item) == 0xFF)
+        if (GiveMailToMonByItemId(mon, item) == MAIL_NONE)
             return;
     }
     itemBytes[0] = item;
@@ -5468,7 +5468,7 @@ void ChooseMonToGiveMailFromMailbox(void)
 static void TryGiveMailToSelectedMon(u8 taskId)
 {
     struct Pokemon *mon = &gPlayerParty[gPartyMenu.slotId];
-    struct MailStruct *mail;
+    struct Mail *mail;
 
     gPartyMenuUseExitCallback = FALSE;
     mail = &gSaveBlock1Ptr->mail[gPlayerPCItemPageInfo.itemsAbove + PARTY_SIZE + gPlayerPCItemPageInfo.cursorPos];
@@ -5478,8 +5478,8 @@ static void TryGiveMailToSelectedMon(u8 taskId)
     }
     else
     {
-        GiveMailToMon2(mon, mail);
-        ClearMailStruct(mail);
+        GiveMailToMon(mon, mail);
+        ClearMail(mail);
         DisplayPartyMenuMessage(gText_MailTransferredFromMailbox, TRUE);
     }
     ScheduleBgCopyTilemapToVram(2);