[flashrom-gerrit] Change in flashrom[master]: Only write back emulated image if modified

[Namyoon Woo (Code Review)]

Namyoon Woo has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/44907 )

Change subject: Only write back emulated image if modified
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Patch Set 1:

This is to sync with the one in chromiumos repo.
Original patch is https://chromium-review.googlesource.com/c/chromiumos/third_party/flashrom/+....