[PATCH v3] mtd: spi-nor: use guard() in spi_nor_rww_start_exclusive

[Miquel Raynal]

>> Have you seen sashiko's review at 
>> https://sashiko.dev/#/patchset/20260811083111.403453-1-runyu.xiao%40seu.edu.cn?
>>
>> Both concerns look valid to me. Do you think you can allocate time to
>> fix them?
>
> Sashiko is becoming a nightmare. I'll add this to my todo list, but if
> someone in lack of technical challenge wants to propose fixes, be my
> guest.

Actually, the might_sleep() warning seems to be an hallucination. It
mixes different concepts in its explanation (might_sleep() is not a
problem here, we are in process context) and I believe it got mislead by
the current state of the code which lacks a mutex_unlock(). The second
issue is definitely not "high" and only touches legacy
spi-nor-controllers. This is worth fixing though.

Thanks,
Miquèl