Change in flashrom[master]: layout: Use linked list for `struct romentry`

[Angel Pons (Code Review)]

Attention is currently required from: Nico Huber, Edward O'Callaghan, Daniel Campello, Anastasia Klimchuk.
Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/33521 )

Change subject: layout: Use linked list for `struct romentry`
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Patch Set 8:

(3 comments)

File layout.c:

https://review.coreboot.org/c/flashrom/+/33521/comment/688a6790_df0f841c 
PS8, Line 388: 	*layout = malloc(sizeof(**layout));
Given that you memset() the allocated space afterwards, use calloc() instead?

https://review.coreboot.org/c/flashrom/+/33521/comment/903fcdc0_b1e25a90 
PS8, Line 418: entry->next	= layout->head;
> I missed the fact that in the beginning when layout has no entries, layout->head is null (or maybe undefined).

It's null, flashrom_layout_new() zero-initialises the newly-allocated `struct layout`. The null pointer signals the end of the linked list.

https://review.coreboot.org/c/flashrom/+/33521/comment/99b9de11_72f8a74f 
PS8, Line 458: if (layout == global_layout)
             : 		return;
             : 
             : 	while (layout && layout->head) {
             : 		struct romentry *const entry = layout->head;
             : 		layout->head = entry->next;
             : 		free(entry->file);
             : 		free(entry->name);
             : 		free(entry);
             : 	}
             : 	free(layout);
Given that `layout` is not modified in the while loop, how about evaluating it once?

if (!layout || layout == global_layout)
    return;

while (layout->head) {
    struct romentry *const entry = layout->head;
    layout->head = entry->next;
    free(entry->file);
    free(entry->name);
    free(entry);
 }
 free(layout);