qmp: Fix argument name in error message of device-list-properties

The argument is called "typename", not "name".

[Thanks to Markus for correcting the commit message]

Signed-off-by: Lin Ma <lma@suse.com>
Message-Id: <20170125052703.23571-1-lma@suse.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>