Change in flashrom[master]: tests: Set up mock chip memory in consistent and predictable way

[Anastasia Klimchuk (Code Review)]

Attention is currently required from: Nico Huber, Paul Menzel, Angel Pons.
Anastasia Klimchuk has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/59237 )

Change subject: tests: Set up mock chip memory in consistent and predictable way
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Patch Set 7:

(2 comments)

File tests/chip.c:

https://review.coreboot.org/c/flashrom/+/59237/comment/e3b8045c_dad901b5 
PS6, Line 33: 	.buf = { MOCK_CHIP_CONTENT },
> This only initialises the first element of `buf`, the rest of the array is initialised to 0. […]

Yes it is misleading: I misled myself :(
I will keep {0} here as it was before, that's a good idea. And yes, setup_chip is expected to be called at the beginning of every test anyway.

https://review.coreboot.org/c/flashrom/+/59237/comment/f0b9efa9_a3860d99 
PS6, Line 97: 	memset(&g_chip_state.buf[0], MOCK_CHIP_CONTENT, MOCK_CHIP_SIZE);
> How about: […]

Done