[7.0] Admin order interface displays invalid user link for pending/incomplete checkout orders

[thomasplevy]

Reproduction Steps

• Initiate checkout using PayPal CP on 7.0-alpha.x
• Abandon checkout before approving the PayPal payment
• View the pending order on the admin panel

Expected Behavior

• The Buyer Name should not be a link because the user does not yet exist in the WP database

Actual Behavior

• The Buyer Name is a link but since the user doesn't exist it links to the current user's user profile screen.