Rename battlerId to battler for consistency (#2126)

include/battle_records.h

@@ -4,7 +4,7 @@
 extern u8 gRecordsWindowId;
 
 void ClearPlayerLinkBattleRecords(void);
-void UpdatePlayerLinkBattleRecords(s32 battlerId);
+void UpdatePlayerLinkBattleRecords(s32 battler);
 void ShowLinkBattleRecords(void);
 void RemoveRecordsWindow(void);
 void ShowTrainerHillRecords(void);