fixed out of bounds reads

Thanks to Eric Sesterhenn from X41 D-SEC GmbH
for reporting and suggesting security fixes.
static void add_acl_entry(sc_file_t *file, int op, u8 byte)
{
	unsigned int method, key_ref = SC_AC_KEY_REF_NONE;

	switch (byte >> 4) {
	case 0:
		method = SC_AC_NONE;
		break;
	case 1:
		method = SC_AC_CHV;
		key_ref = 1;
		break;
	case 2:
		method = SC_AC_CHV;
		key_ref = 2;
		break;
	case 4:
		method = SC_AC_TERM;
		break;
	case 15:
		method = SC_AC_NEVER;
		break;
	default:
		method = SC_AC_UNKNOWN;
		break;
	}
	sc_file_add_acl_entry(file, op, method, key_ref);
}

static void add_acl_entry(sc_file_t *file, int op, u8 byte)
{
	unsigned int method, key_ref = SC_AC_KEY_REF_NONE;

	switch (byte >> 4) {
	case 0:
		method = SC_AC_NONE;
		break;
	case 1:
		method = SC_AC_CHV;
		key_ref = 1;
		break;
	case 2:
		method = SC_AC_CHV;
		key_ref = 2;
		break;
	case 4:
		method = SC_AC_TERM;
		break;
	case 15:
		method = SC_AC_NEVER;
		break;
	default:
		method = SC_AC_UNKNOWN;
		break;
	}
	sc_file_add_acl_entry(file, op, method, key_ref);
}
