LU-16374 ldiskfs: round-up enc file size

LU-16374 ldiskfs: round-up enc file size

When accessing encrypted files on targets mounted as ldiskfs, the
sizes must be rounded up to the next encryption block size. This is
required in order to read or write full encryption blocks.

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I6d08a2eb34f0dff864891a4e3e77977688412ec8
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49410
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Artem Blagodarenko <ablagodarenko@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>