Resolved some compiler warnings (#6047)

Co-authored-by: Aleos <aleos89@users.noreply.github.com>

src/map/battle.cpp

@@ -6055,9 +6055,9 @@ static struct Damage battle_calc_weapon_attack(struct block_list *src, struct bl
 
 			ATK_ADD(wd.damage, wd.damage2, sstatus->max_hp - sstatus->hp);
 			if(sc && sc->data[SC_COMBO] && sc->data[SC_COMBO]->val1 == SR_FALLENEMPIRE) {
-				ATK_ADD(wd.damage, wd.damage2, (sstatus->max_sp * bonus) + 40 * status_get_lv(src));
+				ATK_ADD(wd.damage, wd.damage2, static_cast<int64>(sstatus->max_sp * bonus) + 40 * status_get_lv(src));
 			} else
-				ATK_ADD(wd.damage, wd.damage2, (sstatus->sp * bonus) + 10 * status_get_lv(src));
+				ATK_ADD(wd.damage, wd.damage2, static_cast<int64>(sstatus->sp * bonus) + 10 * status_get_lv(src));
 		}
 			break;
 		case MH_TINDER_BREAKER: