qapi/parser: fix unused check_args_section arguments

qapi/parser: fix unused check_args_section arguments

Pylint informs us we're not using these arguments. Oops, it's
right. Correct the error message and remove the remaining unused
parameter.

Fix test output now that the error message is improved.

Fixes: e151941d1b
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210930205716.1148693-4-jsnow@redhat.com>
[Commit message formatting tweaked]
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>