Merge "fs_mgr: Clear AvbOps struct."

    // We only need to provide the implementation of read_from_partition()

    // operation since that's all what is being used by the avb_slot_verify().

    // Other I/O operations are only required in bootloader but not in

    // user-space so we set them as dummy operations.

    // user-space so we set them as dummy operations. Also zero the entire

    // struct so operations added in the future will be set to NULL.

    memset(&avb_ops_, 0, sizeof(AvbOps));

    avb_ops_.read_from_partition = read_from_partition;

    avb_ops_.read_rollback_index = dummy_read_rollback_index;

    avb_ops_.validate_vbmeta_public_key = dummy_validate_vbmeta_public_key;