The commit fixes the case:
If variables in RTC RAM have been moved around by the linker,
they will be filled with garbage data. Any reset other than OTA would work fine
because the variables would still be initialized from the initial bootup.
So now system time will be valid even after OTA.
Closes https://github.com/espressif/esp-idf/issues/9448
User's custom data are not taken into account during the CRC calculation anymore.
Which means taht the retained mem structure is not systematically erased
on each reboot anymore.