Fixing flavor access __repr__ method

The Flavor Access __repr__ method was crashing because
it was using a non-existing attribute called "name".
On this fix, this method will now return the following:

<FlavorAccess flavor id: {flavor_id}, tenant id: {tenant_id}>

Closes-bug: #1331602

Change-Id: Ia2c24312e59e6c0aba1009766a15d390dc2721b1
Merge "Fixing flavor access __repr__ method"