remove asm/battle_ai.o from ld script

ld_script.txt

@@ -153,7 +153,6 @@ SECTIONS {
         asm/slot_machine.o(.text);
         asm/contest_painting.o(.text);
         src/battle_ai.o(.text);
-        asm/battle_ai.o(.text);
         asm/trader.o(.text);
         asm/starter_choose.o(.text);
         asm/wallclock.o(.text);