Fix typo in controlnet docs

[MrSyee]

What does this PR do?

In ControlNet with SDXL docs, I found a typo in code example.
If you don't fix this code, you'll get an error:

Traceback (most recent call last):s: 100%|███████████████████████████████| 335M/335M [00:16<00:00, 22.4MB/s]
  File "/home/khwankim_dc/workspace/TIL/diffusers/controlnet/sdxl.py", line 49, in <module>7<00:26, 275MB/s]
    output = pipe(model.safetensors: 100%|█████████████████████████████▉| 10.2G/10.3G [00:54<00:00, 195MB/s]
  File "/home/khwankim_dc/anaconda3/envs/diffusers/lib/python3.10/site-packages/torch/autograd/grad_mode.py", line 27, in decorate_context
    return func(*args, **kwargs)
  File "/home/khwankim_dc/anaconda3/envs/diffusers/lib/python3.10/site-packages/diffusers/pipelines/controlnet/pipeline_controlnet_sd_xl.py", line 906, in __call__
    self.check_inputs(
  File "/home/khwankim_dc/anaconda3/envs/diffusers/lib/python3.10/site-packages/diffusers/pipelines/controlnet/pipeline_controlnet_sd_xl.py", line 531, in check_inputs
    self.check_image(image, prompt, prompt_embeds)
  File "/home/khwankim_dc/anaconda3/envs/diffusers/lib/python3.10/site-packages/diffusers/pipelines/controlnet/pipeline_controlnet_sd_xl.py", line 641, in check_image
    raise ValueError(
ValueError: If image batch size is not 1, image batch size must be same as prompt batch size. image batch size: 1024, prompt batch size: 1

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[DN6]

Nice!

[patrickvonplaten]

Great catch!