Item vfs.dev.discovery  doesn't have any parameters, but, when using Zabbix agent 2 - it is possible to add anything as the parameter, and the item will continue working as usual, which is confusing.

Steps to reproduce:
Test the item vfs.dev.discovery using Zabbix agent 2, add any parameters in the key.

For example:

./sbin/zabbix_agent2 -t vfs.dev.discovery[test,parameters]

Result:
The list of devices is returned as usual (same as for vfs.dev.discovery without parameters)

Expected:
The behavior should be same as for Zabbix agent: should not be possible to use / test vfs.dev.discovery with any parameters, message "Item does not allow parameters." should be displayed.

See example, using Zabbix agent:

./sbin/zabbix_agentd -t vfs.dev.discovery[test,parameters]
vfs.dev.discovery[test,parameters]            [m|ZBX_NOTSUPPORTED] [Item does not allow parameters.]