[M] Change in flashrom[master]: flashrom_tester: Change string types to path types where appropriate

[Evan Benn (Code Review)]

Attention is currently required from: Angel Pons, Peter Marheine.

Evan Benn has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/69064 )

Change subject: flashrom_tester: Change string types to path types where appropriate
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Patch Set 2:

(2 comments)

Commit Message:

https://review.coreboot.org/c/flashrom/+/69064/comment/865ac338_a68bb7f3 
PS1, Line 7: String
> `str` not `String`, a `String` is a heap allocated "string" while a `str` is a stack allocated "stri […]

good point, i changed to 'string' as the rust book does

https://review.coreboot.org/c/flashrom/+/69064/comment/3d96ac1a_92c2219a 
PS1, Line 9: String
> s/String/Stack allocated str's with life-time 'a'/

Done