Fix typo, make pyoperation_xml use explicit.
The only use of the old-style smtk_operation_xml is for python, make it explicit. Fix typo from arg.
Should have merged this before rgg. @ben.boeckel
The only use of the old-style smtk_operation_xml is for python, make it explicit. Fix typo from arg.
Should have merged this before rgg. @ben.boeckel