Use friendship event constants

src/battle_main.c

@@ -718,7 +718,7 @@ static void CB2_InitBattleInternal(void)
     gSaveBlock2Ptr->frontier.disableRecordBattle = FALSE;
 
     for (i = 0; i < PARTY_SIZE; i++)
-        AdjustFriendship(&gPlayerParty[i], 3);
+        AdjustFriendship(&gPlayerParty[i], FRIENDSHIP_EVENT_LEAGUE_BATTLE);
 
     gBattleCommunication[MULTIUSE_STATE] = 0;
 }