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

[Angel Pons (Code Review)]

Attention is currently required from: Nico Huber, Paul Menzel, Anastasia Klimchuk.
Angel Pons 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 6: Code-Review+1

(2 comments)

File tests/chip.c:

https://review.coreboot.org/c/flashrom/+/59237/comment/29291648_c2e54296 
PS6, Line 33: 	.buf = { MOCK_CHIP_CONTENT },
This only initialises the first element of `buf`, the rest of the array is initialised to 0. I see it gets filled later on, but I find this potentially misleading.

I'd remove the static initialiser (or leave it to explicitly initialise to 0) and put the actual initialisation code in a helper function just below.

https://review.coreboot.org/c/flashrom/+/59237/comment/0541c335_3cc7c8fe 
PS6, Line 97: 	memset(&g_chip_state.buf[0], MOCK_CHIP_CONTENT, MOCK_CHIP_SIZE);
How about:

memset(g_chip_state.buf, MOCK_CHIP_CONTENT, sizeof(g_chip_state.buf));