LinkSpec without name cannot be written

[rly]

Description

When a spec yaml contains:

groups:
- neurodata_type_def: A
  doc: ...
  links:
  - target_type: Device
    doc: Cameras used to record the videos.
    quantity: '*'  # this fails with any quantity ('?', '+', 1, '*'), but no name is often associated with quantity '*'

And a user provides a device, the following error is raised:

AttributeError: 'LinkSpec' object has no attribute 'data_type_def'
..\hdmf\src\hdmf\spec\spec.py:1014: AttributeError

Environment

Python Executable: Conda
Python Version: Python 3.9
Operating System: Windows
HDMF Version: dev

Checklist

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