[rear-devel] [rear/rear] 898620: Update write-protect-functions.sh

[Johannes Meixner]

  Branch: refs/heads/jsmeix-write-protect
  Home:   https://github.com/rear/rear
  Commit: 898620b509571e881797f5f5b475eae49d997736
      https://github.com/rear/rear/commit/898620b509571e881797f5f5b475eae49d997736
  Author: Johannes Meixner <jsmeix at suse.com>
  Date:   2021-11-05 (Fri, 05 Nov 2021)

  Changed paths:
    M usr/share/rear/lib/write-protect-functions.sh

  Log Message:
  -----------
  Update write-protect-functions.sh

Do not use SERIAL disk serial number, cf.
https://github.com/rear/rear/pull/2703#issuecomment-961875897