Pass entity_id in display context to commerce_product_reference_commerce_product_uri

I was debugging an issue with 7.x-1.6 where the commerce product display node view of a product kept linking to the administrative view of the product ( the product edit form ) instead of through to the product display node view page.

The settings appeared correct for the teaser view mode on the product, with the image set to link to "Content"

It appears the issue occurs because in:

commerce_product_reference_commerce_product_uri

The entity_id value is never passed, so the node uri isn't returned, and instead defaults to the admin product page.

The attached patch adds the entity_id parameter to the product display_context so the commerce_product_reference field URI can be generated correctly, linking it through to the display node from product field teaser view.

Please review and commit if suitable, thanks.