MSI-920: Fixed incorrect test (during order cancellation)

[seruymt]

Description

Fixed incorrect test (during order cancellation)

Fixed Issues (if relevant)

1. We can't process inventory cancellation for non existing product (in test - sku: simple2)

Manual testing scenarios

1. none

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[seruymt]

If we can use the same product Id for order items, then we can use the same Sku

[VladimirZaets]

@seruymt It is incorrect to set the same SKU for two product in an order. You can use another fixture to obtain the same behavior.

[magento-engcom-team]

Hi @seruymt. Thank you for your contribution.
Changes from your Pull Request will be available with the upcoming 2.3.0 release.