Change in flashrom[master]: stlinkv3_spi.c: Refactor singleton states into reentrant pattern

[Edward O'Callaghan (Code Review)]

Attention is currently required from: Nico Huber, Angel Pons, Anastasia Klimchuk.
Edward O'Callaghan has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/54042 )

Change subject: stlinkv3_spi.c: Refactor singleton states into reentrant pattern
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Patch Set 1:

(1 comment)

File stlinkv3_spi.c:

https://review.coreboot.org/c/flashrom/+/54042/comment/616cea9f_5f4625a3 
PS1, Line 533: stlinkv3_spi_open(sck_freq_kHz, stlinkv3_handle
> It's just the one more `goto err_exit` that you added (in case calloc […]

Not to derail but Nico no one is "And blaming the existing code for it seems odd." please don't jump to conclusions. Thanks for noticing that path though the shutdown fn, I was thinking of a different that is all.