usb: gadget: fsl: Fix a wrong judgment in fsl_udc_probe()

[Tang Bin]

Hi Markus:

On 2020/4/10 16:30, Markus Elfring wrote:
>> Hardware experiments show that the negative return value is not just "-EPROBE_DEFER".
> How much will this specific error code influence our understanding
> of the discussed software situation?
>
 From my superficial knowledge, I think we should not  think about it 
too complicated. The return value is just zero or negative, and for 
these negative return value, such as 
"-ENODEV"、"-ENXIO"、"-ENOENT"、“EPROBE_DEFER”，may be the same 
effect。But“-EPROBE_DEFER”has another  importment function: Driver 
requested deferred probing，which is used in cases where the dependency 
resource is not ready during the driver initialization process.
>>>> +        ret = udc_controller->irq ? : -ENODEV;
>>> Will it be clearer to specify values for all cases in such a conditional operator
>>> (instead of leaving one case empty)?
>> I don't know what you mean of "instead of leaving one case empty".
> I suggest to reconsider also the proposed specification “… ? : …”.

What you mean is the way I'm written？

I have provided two ways of patching, both functional can be verified on 
hardware.

Thanks for your patience.

Tang Bin