refac: rename func_80322FE4 to overlay_init

src/core2/code_9B990.c

@@ -366,7 +366,7 @@ void func_80322FBC(void){
 
 void func_80322FDC(void){ return; }
 
-void func_80322FE4(void){
+void overlay_init(void){
     int i;
     s32 overlay_id;
     func_80356714();

src/core2/code_AD5B0.c

@@ -191,7 +191,7 @@ void func_80334B20(enum map_e arg0, s32 arg1, s32 arg2) {
     D_803835D0.unk0 = 3;
     D_803835D0.map_4 = arg0;
     D_803835D0.unk8 = arg1;
-    func_80322FE4();
+    overlay_init();
     func_80335110(1);
     func_80335128(1);
     func_802D2CB8();